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Multiplicities of positive and negative pions, kaons and unidentified hadrons from deep-inelastic scattering of muons off a liquid hydrogen target
G. D. Alexeev, M. G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C. D. R. Azevedo, B. Badelek, J. Barth, R. Beck, J. Beckers, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, W.-C. Chang, C. Chatterjee, et al (150)
Oct 17 2024 hep-ex hep-ph arXiv:2410.12005v1

@misc{2410.12005, author = {G.~D.~Alexeev and M.~G.~Alexeev and C.~Alice and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.~D.~R.~Azevedo and B.~Badelek and J.~Barth and R.~Beck and J.~Beckers and Y.~Bedfer and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and S.-U.~Chung and A.~Cicuttin and P.~M.~M.~Correia and M.~L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.~S.~Dasgupta and S.~Dasgupta and F.~Delcarro and I.~Denisenko and O.~Yu.~Denisov and S.~V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Dünnweber and R.~R.~Dusaev and D.~Ecker and D.~Eremeev and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~J.~Flöthner and W.~Florian and J.~M.~Friedrich and V.~Frolov and L.G.~Garcia Ordòñez and O.~P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and M.~Grüner and A.~Guskov and P.~Haas and D.~von Harrach and M.~Hoffmann and N.~d'Hose and C.-Y.~Hsieh and S.~Ishimoto and A.~Ivanov and T.~Iwata and V.~Jary and R.~Joosten and E.~Kabuß and F.~Kaspar and A.~Kerbizi and B.~Ketzer and A.~Khatun and G.~V.~Khaustov and F.~Klein and J.~H.~Koivuniemi and V.~N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and A.~Yu.~Korzenev and A.~M.~Kotzinian and O.~M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Kunne and K.~Kurek and R.~P.~Kurjata and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.~E.~Lyubovitskij and A.~Maggiora and N.~Makke and G.~K.~Mallot and A.~Maltsev and A.~Martin and J.~Marzec and J.~Matoušek and T.~Matsuda and C.~Menezes Pires and F.~Metzger and W.~Meyer and Yu.~V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and D.~Miura and Y.~Miyachi and R.~Molina and A.~Moretti and A.~Nagaytsev and D.~Neyret and M.~Niemiec and J.~Nový and W.-D.~Nowak and G.~Nukazuka and A.~G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pešek and D.~V.~Peshekhonov and M.~Pešková and S.~Platchkov and J.~Pochodzalla and V.~A.~Polyakov and C.~Quintans and G.~Reicherz and C.~Riedl and D.~I.~Ryabchikov and A.~Rychter and A.~Rymbekova and V.~D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.~A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and L.~Sinha and D.~Spülbeck and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and S.~Tessaro and F.~Tessarotto and A.~Thiel and F.~Tosello and A.~Townsend and T.~Triloki and V.~Tskhay and B.~Valinoti and B.~M.~Veit and J.F.C.A.~Veloso and A.~Vijayakumar and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and M.~Ziembicki}, title = {{M}ultiplicities of positive and negative pions, kaons and unidentified hadrons from deep-inelastic scattering of muons off a liquid hydrogen target}, year = {2024}, eprint = {2410.12005}, note = {arXiv:2410.12005v1} }
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The multiplicities of positive and negative pions, kaons and unidentified hadrons produced in deep-inelastic scattering are measured in bins of the Bjorken scaling variable $x$, the relative virtual-photon energy $y$ and the fraction of the virtual-photon energy transferred to the final-state hadron $z$. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam of both electric charges and a liquid hydrogen target. These measurements cover the kinematic domain with photon virtuality $Q^2 > 1$ (GeV/$c)^2$, $0.004 < x < 0.4$, $0.1 < y < 0.7$ and $0.2 < z < 0.85$, in accordance with the kinematic domain used in earlier published COMPASS multiplicity measurements with an isoscalar target. The calculation of radiative corrections was improved by using the Monte Carlo generator DJANGOH, which results in up to 12\% larger corrections in the low-$x$ region.
Fluorescence Imaging of Individual Ions and Molecules in Pressurized Noble Gases for Barium Tagging in $^{136}$Xe
NEXT Collaboration, N. Byrnes, E. Dey, F.W. Foss, B.J.P. Jones, R. Madigan, A. McDonald, R.L. Miller, K.E. Navarro, L.R. Norman, D.R. Nygren, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, F. Auria-Luna, S. Ayet, et al (95)
Jun 25 2024 physics.ins-det hep-ex nucl-ex arXiv:2406.15422v1

@misc{2406.15422, author = {NEXT Collaboration and N.~Byrnes and E.~Dey and F.W.~Foss and B.J.P.~Jones and R.~Madigan and A.~McDonald and R.L.~Miller and K.E.~Navarro and L.R.~Norman and D.R.~Nygren and C.~Adams and H.~Almazán and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and L.~Arazi and I.J.~Arnquist and F.~Auria-Luna and S.~Ayet and C.D.R.~Azevedo and J.E.~Barcelon and K.~Bailey and F.~Ballester and M.~del Barrio-Torregrosa and A.~Bayo and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Brodolin and S.~Cárcel and A.~Castillo and S.~Cebrián and E.~Church and L.~Cid and C.A.N.~Conde and T.~Contreras and F.P.~Cossío and G.~Díaz and T.~Dickel and C.~Echevarria and M.~Elorza and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and Z.~Freixa and J.~García-Barrena and J.J.~Gómez-Cadenas and R.~González and J.W.R.~Grocott and R.~Guenette and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero-Gómez and V.~Herrero and C.~Hervés Carrete and P.~Ho and Y.~Ifergan and F.~Kellerer and L.~Larizgoitia and A.~Larumbe and P.~Lebrun and F.~Lopez and N.~López-March and R.D.P.~Mano and A.P.~Marques and J.~Martín-Albo and G.~Martínez-Lema and M.~Martínez-Vara and K.~Mistry and J.~Molina-Canteras and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and P.~Novella and A.~Nuñez and E.~Oblak and J.~Palacio and B.~Palmeiro and A.~Para and I.~Parmaksiz and A.~Pazos and J.~Pelegrin and M.~Pérez Maneiro and M.~Querol and A.B.~Redwine and J.~Renner and I.~Rivilla and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and M.~Seemann and I.~Shomroni and P.A.O.C.~Silva and A.~Simón and S.R.~Soleti and M.~Sorel and J.~Soto-Oton and J.M.R.~Teixeira and S.~Teruel-Pardo and J.F.~Toledo and C.~Tonnelé and J.~Torrent and A.~Trettin and A.~Usón and P.R.G.~Valle and J.F.C.A.~Veloso and J.~Waiton and A.~Yubero-Navarro}, title = {{F}luorescence {I}maging of {I}ndividual {I}ons and {M}olecules in {P}ressurized {N}oble {G}ases for {B}arium {T}agging in $^{136}${X}e}, year = {2024}, eprint = {2406.15422}, note = {arXiv:2406.15422v1} }
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The imaging of individual Ba$^{2+}$ ions in high pressure xenon gas is one possible way to attain background-free sensitivity to neutrinoless double beta decay and hence establish the Majorana nature of the neutrino. In this paper we demonstrate selective single Ba$^{2+}$ ion imaging inside a high-pressure xenon gas environment. Ba$^{2+}$ ions chelated with molecular chemosensors are resolved at the gas-solid interface using a diffraction-limited imaging system with scan area of 1$\times$1~cm$^2$ located inside 10~bar of xenon gas. This new form of microscopy represents an important enabling step in the development of barium tagging for neutrinoless double beta decay searches in $^{136}$Xe, as well as a new tool for studying the photophysics of fluorescent molecules and chemosensors at the solid-gas interface.
Measurement of Energy Resolution with the NEXT-White Silicon Photomultipliers
T. Contreras, B. Palmeiro, H. Almazán, A. Para, G. Martínez-Lema, R. Guenette, C. Adams, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, F. Auria-Luna, S. Ayet, C.D.R. Azevedo, K. Bailey, F. Ballester, M. del Barrio-Torregrosa, A. Bayo, J.M. Benlloch-Rodríguez, et al (90)
Jun 03 2024 hep-ex physics.ins-det arXiv:2405.20427v2

@misc{2405.20427, author = {T.~Contreras and B.~Palmeiro and H.~Almazán and A.~Para and G.~Martínez-Lema and R.~Guenette and C.~Adams and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and L.~Arazi and I.J.~Arnquist and F.~Auria-Luna and S.~Ayet and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and M.~del Barrio-Torregrosa and A.~Bayo and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Brodolin and N.~Byrnes and S.~Cárcel and A.~Castillo and S.~Cebrián and E.~Church and L.~Cid and C.A.N.~Conde and F.P.~Cossío and E.~Dey and G.~Díaz and T.~Dickel and C.~Echevarria and M.~Elorza and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and F.W.~Foss and Z.~Freixa and J.~García-Barrena and J.J.~Gómez-Cadenas and R.~González and J.W.R.~Grocott and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero-Gómez and V.~Herrero and C.~Hervés Carrete and Y.~Ifergan and B.J.P.~Jones and F.~Kellerer and L.~Larizgoitia and A.~Larumbe and P.~Lebrun and F.~Lopez and N.~López-March and R.~Madigan and R.D.P.~Mano and A.P.~Marques and J.~Martín-Albo and M.~Martínez-Vara and R.L.~Miller and K.~Mistry and J.~Molina-Canteras and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and K.E.~Navarro and P.~Novella and A.~Nuñez and D.R.~Nygren and E.~Oblak and J.~Palacio and I.~Parmaksiz and A.~Pazos and J.~Pelegrin and M.~Pérez Maneiro and M.~Querol and A.B.~Redwine and J.~Renner and I.~Rivilla and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and M.~Seemann and I.~Shomroni and P.A.O.C.~Silva and A.~Simón and S.R.~Soleti and M.~Sorel and J.~Soto-Oton and J.M.R.~Teixeira and S.~Teruel-Pardo and J.F.~Toledo and C.~Tonnelé and J.~Torrent and A.~Trettin and A.~Usón and P.R.G.~Valle and J.F.C.A.~Veloso and J.~Waiton and A.~Yubero-Navarro}, title = {{M}easurement of {E}nergy {R}esolution with the {NEXT}-{W}hite {S}ilicon {P}hotomultipliers}, year = {2024}, eprint = {2405.20427}, note = {arXiv:2405.20427v2} }
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The NEXT-White detector, a high-pressure gaseous xenon time projection chamber, demonstrated the excellence of this technology for future neutrinoless double beta decay searches using photomultiplier tubes (PMTs) to measure energy and silicon photomultipliers (SiPMs) to extract topology information. This analysis uses $^{83m}\text{Kr}$ data from the NEXT-White detector to measure and understand the energy resolution that can be obtained with the SiPMs, rather than with PMTs. The energy resolution obtained of (10.9 $\pm$ 0.6) $\%$, full-width half-maximum, is slightly larger than predicted based on the photon statistics resulting from very low light detection coverage of the SiPM plane in the NEXT-White detector. The difference in the predicted and measured resolution is attributed to poor corrections, which are expected to be improved with larger statistics. Furthermore, the noise of the SiPMs is shown to not be a dominant factor in the energy resolution and may be negligible when noise subtraction is applied appropriately, for high-energy events or larger SiPM coverage detectors. These results, which are extrapolated to estimate the response of large coverage SiPM planes, are promising for the development of future, SiPM-only, readout planes that can offer imaging and achieve similar energy resolution to that previously demonstrated with PMTs.
High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons
G. D. Alexeev, M. G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, S. Asatryan, K. Augsten, W. Augustyniak, C. D. R. Azevedo, B. Badelek, J. Barth, R. Beck, J. Beckers, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, W.-C. Chang, et al (167)
Jan 02 2024 hep-ex hep-ph arXiv:2401.00309v1

@misc{2401.00309, author = {G.~D.~Alexeev and M.~G.~Alexeev and C.~Alice and A.~Amoroso and V.~Andrieux and V.~Anosov and S.~Asatryan and K.~Augsten and W.~Augustyniak and C.~D.~R.~Azevedo and B.~Badelek and J.~Barth and R.~Beck and J.~Beckers and Y.~Bedfer and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.~G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.~M.~M.~Correia and M.~L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.~S.~Dasgupta and S.~Dasgupta and F.~Delcarro and I.~Denisenko and O.~Yu.~Denisov and S.~V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Dunnweber and R.~R.~Dusaev and D.~Ecker and D.~Eremeev and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~J.~Flothner and W.~Florian and J.~M.~Friedrich and V.~Frolov and L.G.~Garcia Ordonez and F.~Gautheron and O.~P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and M.~Gruner and A.~Guskov and P.~Haas and D.~von Harrach and M.~Hoffmann and A.~Hoghmrtsyan and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and V.~Jary and R.~Joosten and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and A.~Khatun and G.~V.~Khaustov and T.~Klasek and F.~Klein and J.~H.~Koivuniemi and V.~N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and V.~F.~Konstantinov and A.~Yu.~Korzenev and A.~M.~Kotzinian and O.~M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and F.~Kunne and K.~Kurek and R.~P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.~E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makke and G.~K.~Mallot and A.~Maltsev and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and C.~Menezes Pires and F.~Metzger and M.~Meyer and W.~Meyer and Yu.~V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and D.~Miura and Y.~Miyachi and R.~Molina and A.~Moretti and A.~Movsisyan and A.~Nagaytsev and D.~Neyret and M.~Niemiec and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.~G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.~V.~Peshekhonov and M.~Peskova and S.~Platchkov and J.~Pochodzalla and V.~A.~Polyakov and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and D.~I.~Ryabchikov and A.~Rychter and A.~Rymbekova and V.~D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.~A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and D.~Spulbeck and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and Y.~Takanashi and S.~Tessaro and F.~Tessarotto and A.~Thiel and F.~Tosello and A.~Townsend and T.~Triloki and V.~Tskhay and B.~Valinoti and B.~M.~Veit and J.F.C.A.~Veloso and B.~Ventura and A.~Vijayakumar and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and M.~Ziembicki}, title = {{H}igh-statistics measurement of {C}ollins and {S}ivers asymmetries for transversely polarised deuterons}, year = {2024}, eprint = {2401.00309}, note = {arXiv:2401.00309v1} }
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New results are presented on a high-statistics measurement of Collins and Sivers asymmetries of charged hadrons produced in deep inelastic scattering of muons on a transversely polarised $^6$LiD target. The data were taken in 2022 with the COMPASS spectrometer using the 160 \gevv muon beam at CERN, balancing the existing data on transversely polarised proton targets. The first results from about two-thirds of the new data have total uncertainties smaller by up to a factor of three compared to the previous deuteron measurements. Using all the COMPASS proton and deuteron results, both the transversity and the Sivers distribution functions of the $u$ and $d$ quark, as well as the tensor charge in the measured $x$-range are extracted. In particular, the accuracy of the $d$ quark results is significantly improved.
Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process
G. D. Alexeev, M. G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C. D. R. Azevedo, B. Badelek, J. Barth, R. Beck, J. Beckers, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, W.-C. Chang, C. Chatterjee, et al (164)
Jan 01 2024 hep-ex hep-ph arXiv:2312.17379v1

@misc{2312.17379, author = {G.~D.~Alexeev and M.~G.~Alexeev and C.~Alice and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.~D.~R.~Azevedo and B.~Badelek and J.~Barth and R.~Beck and J.~Beckers and Y.~Bedfer and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.~G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.~M.~M.~Correia and M.~L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.~S.~Dasgupta and S.~Dasgupta and F.~Delcarro and I.~Denisenko and O.~Yu.~Denisov and S.~V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Dunnweber and R.~R.~Dusaev and D.~Ecker and D.~Eremeev and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~J.~Flothner and W.~Florian and J.~M.~Friedrich and V.~Frolov and L.G.~Garcia Ordonez and F.~Gautheron and O.~P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and M.~Gruner and A.~Guskov and P.~Haas and D.~von Harrach and R.~Heitz and M.~Hoffmann and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and V.~Jary and R.~Joosten and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and A.~Khatun and G.~V.~Khaustov and F.~Klein and J.~H.~Koivuniemi and V.~N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and V.~F.~Konstantinov and A.~Yu.~Korzenev and A.~M.~Kotzinian and O.~M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and F.~Kunne and K.~Kurek and R.~P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.~E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makke and G.~K.~Mallot and A.~Maltsev and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and C.~Menezes Pires and F.~Metzger and M.~Meyer and W.~Meyer and Yu.~V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and D.~Miura and Y.~Miyachi and R.~Molina and A.~Moretti and A.~Nagaytsev and D.~Neyret and M.~Niemiec and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.~G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.~V.~Peshekhonov and M.~Peskova and S.~Platchkov and J.~Pochodzalla and V.~A.~Polyakov and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and D.~I.~Ryabchikov and A.~Rychter and A.~Rymbekova and V.~D.~Samoylenko and A.~Sandacz and S.~Sarkar and T.~Savada and I.~A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and D.~Spulbeck and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and S.~Tessaro and F.~Tessarotto and A.~Thiel and F.~Tosello and A.~Townsend and T.~Triloki and V.~Tskhay and B.~Valinoti and B.~M.~Veit and J.F.C.A.~Veloso and B.~Ventura and A.~Vijayakumar and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and M.~Ziembicki}, title = {{F}inal {COMPASS} results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced {D}rell-{Y}an process}, year = {2024}, eprint = {2312.17379}, note = {arXiv:2312.17379v1} }
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The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c $\pi^{-}$ beam impinging on a transversely polarised ammonia target. Combining the data of both years, we present final results on the amplitudes of the five azimuthal modulations in the dimuon production cross section. Three of these transverse-spin-dependent azimuthal asymmetries (TSAs) probe the nucleon leading-twist Sivers, transversity, and pretzelosity transverse-momentum dependent (TMD) parton distribution functions (PDFs). The other two are induced by subleading effects. These TSAs provide unique new inputs for the study of the nucleon TMD PDFs and their universality properties. In particular, the Sivers TSA observed in this measurement is consistent with the fundamental QCD prediction of a sign change of naive time-reversal-odd TMD PDFs when comparing the Drell-Yan process with semi-inclusive measurements of deep inelastic scattering. Also, within the context of model predictions, the observed transversity TSA is consistent with the expectation of a sign change for the Boer-Mulders function.
Demonstration of Event Position Reconstruction based on Diffusion in the NEXT-White Detector
J.Haefner, K.E.Navarro, R.Guenette, B.J.P.Jones, A.Tripathi, C.Adams, H.Almazán, V.Álvarez, B.Aparicio, A.I.Aranburu, L.Arazi, I.J.Arnquist, F.Auria-Luna, S.Ayet, C.D.R.Azevedo, K.Bailey, F.Ballester, M.del Barrio-Torregrosa, A.Bayo, J.M.BenllochRodríguez, et al (91)
Nov 08 2023 physics.ins-det hep-ex arXiv:2311.03441v1

@misc{2311.03441, author = {J.Haefner and K.E.Navarro and R.Guenette and B.J.P.Jones and A.Tripathi and C.Adams and H.Almazán and V.Álvarez and B.Aparicio and A.I.Aranburu and L.Arazi and I.J.Arnquist and F.Auria-Luna and S.Ayet and C.D.R.Azevedo and K.Bailey and F.Ballester and M.del Barrio-Torregrosa and A.Bayo and J.M.BenllochRodríguez and F.I.G.M.Borges and A.Brodolin and N.Byrnes and S.Cárcel and J.V.Carrión and S.Cebrián and E.Church and L.Cid and C.A.N.Conde and T.Contreras and F.P.Cossío and E.Dey and G.Díaz and T.Dickel and M.Elorza and J.Escada and R.Esteve and R.Felkai and L.M.P.Fernandes and P.Ferrario and A.L.Ferreira and F.W.Foss and E.D.C.Freitas and Z.Freixa and J.Generowicz and A.Goldschmidt and J.J.Gómez-Cadenas and R.González and J.Grocott and K.Hafidi and J.Hauptman and C.A.O.Henriques and J.A.Hernando Morata and P.Herrero-Gómez and V.Herrero and C.Hervés Carrete and Y.Ifergan and L.Labarga and L.Larizgoitia and A.Larumbe and P.Lebrun and F.Lopez and N.López-March and R.Madigan and R.D.P.Mano and A.P.Marques and J.Martín-Albo and G.Martínez-Lema and M.Martínez-Vara and Z.E.Meziani and R.L.Miller and K.Mistry and J.Molina-Canteras and F.Monrabal and C.M.B.Monteiro and F.J.Mora and J.Muñoz Vidal and P.Novella and A.Nuñez and D.R.Nygren and E.Oblak and J.Palacio and B.Palmeiro and A.Para and I.Parmaksiz and J.Pelegrin and M.Pérez Maneiro and M.Querol and A.B.Redwine and J.Renner and I.Rivilla and J.Rodríguez and C.Rogero and L.Rogers and B.Romeo and C.Romo-Luque and F.P.Santos and J.M.F.~dos Santos and I.Shomroni and A.Simón and S.R.Soleti and M.Sorel and J.Soto-Oton and J.M.R.Teixeira and J.F.Toledo and J.Torrent and A.Trettin and A.Usón and J.F.C.A.Veloso and J.Waiton and J.T.White}, title = {{D}emonstration of {E}vent {P}osition {R}econstruction based on {D}iffusion in the {NEXT}-{W}hite {D}etector}, year = {2023}, eprint = {2311.03441}, note = {arXiv:2311.03441v1} }
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Noble element time projection chambers are a leading technology for rare event detection in physics, such as for dark matter and neutrinoless double beta decay searches. Time projection chambers typically assign event position in the drift direction using the relative timing of prompt scintillation and delayed charge collection signals, allowing for reconstruction of an absolute position in the drift direction. In this paper, alternate methods for assigning event drift distance via quantification of electron diffusion in a pure high pressure xenon gas time projection chamber are explored. Data from the NEXT-White detector demonstrate the ability to achieve good position assignment accuracy for both high- and low-energy events. Using point-like energy deposits from $^{83\mathrm{m}}$Kr calibration electron captures ($E\sim45$keV), the position of origin of low-energy events is determined to $2~$cm precision with bias $< 1$mm. A convolutional neural network approach is then used to quantify diffusion for longer tracks (E$\geq$1.5MeV), yielding a precision of 3cm on the event barycenter. The precision achieved with these methods indicates the feasibility energy calibrations of better than 1% FWHM at Q$_{\beta\beta}$ in pure xenon, as well as the potential for event fiducialization in large future detectors using an alternate method that does not rely on primary scintillation.
Demonstration of neutrinoless double beta decay searches in gaseous xenon with NEXT
NEXT Collaboration, P. Novella, M. Sorel, A. Usón, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, F. Auria-Luna, S. Ayet, C.D.R. Azevedo, K. Bailey, F. Ballester, M. del Barrio-Torregrosa, A. Bayo, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, et al (95)
May 17 2023 nucl-ex hep-ex physics.ins-det arXiv:2305.09435v4

@misc{2305.09435, author = {NEXT Collaboration and P.~Novella and M.~Sorel and A.~Usón and C.~Adams and H.~Almazán and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and L.~Arazi and I.J.~Arnquist and F.~Auria-Luna and S.~Ayet and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and M.~del Barrio-Torregrosa and A.~Bayo and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and S.~Bounasser and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and L.~Cid and C.A.N.~Conde and T.~Contreras and F.P.~Cossío and E.~Dey and G.~Díaz and T.~Dickel and M.~Elorza and J.~Escada and R.~Esteve and A.~Fahs and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and F.W.~Foss and E.D.C.~Freitas and Z.~Freixa and J.~Generowicz and A.~Goldschmidt and J.J.~Gómez-Cadenas and R.~González and J.~Grocott and R.~Guenette and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero-Gómez and V.~Herrero and C.~Hervés Carrete and J.~Ho and P.~Ho and Y.~Ifergan and B.J.P.~Jones and L.~Labarga and L.~Larizgoitia and A.~Larumbe and P.~Lebrun and F.~Lopez and D.~Lopez Gutierrez and N.~López-March and R.~Madigan and R.D.P.~Mano and A.P.~Marques and J.~Martín-Albo and G.~Martínez-Lema and M.~Martínez-Vara and Z.E.~Meziani and R.L.~Miller and K.~Mistry and J.~Molina-Canteras and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and K.E.~Navarro and A.~Nuñez and D.R.~Nygren and E.~Oblak and M.~Odriozola-Gimeno and J.~Palacio and B.~Palmeiro and A.~Para and I.~Parmaksiz and J.~Pelegrin and M.~Pérez Maneiro and M.~Querol and A.B.~Redwine and J.~Renner and I.~Rivilla and J.~Rodríguez and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and S.R.~Soleti and C.~Stanford and J.M.R.~Teixeira and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and T.T.~Vuong and J.~Waiton and J.T.~White}, title = {{D}emonstration of neutrinoless double beta decay searches in gaseous xenon with {NEXT}}, year = {2023}, eprint = {2305.09435}, note = {arXiv:2305.09435v4} }
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The NEXT experiment aims at the sensitive search of the neutrinoless double beta decay in $^{136}$Xe, using high-pressure gas electroluminescent time projection chambers. The NEXT-White detector is the first radiopure demonstrator of this technology, operated in the Laboratorio Subterráneo de Canfranc. Achieving an energy resolution of 1% FWHM at 2.6 MeV and further background rejection by means of the topology of the reconstructed tracks, NEXT-White has been exploited beyond its original goals in order to perform a neutrinoless double beta decay search. The analysis considers the combination of 271.6 days of $^{136}$Xe-enriched data and 208.9 days of $^{136}$Xe-depleted data. A detailed background modeling and measurement has been developed, ensuring the time stability of the radiogenic and cosmogenic contributions across both data samples. Limits to the neutrinoless mode are obtained in two alternative analyses: a background-model-dependent approach and a novel direct background-subtraction technique, offering results with small dependence on the background model assumptions. With a fiducial mass of only 3.50$\pm$0.01 kg of $^{136}$Xe-enriched xenon, 90% C.L. lower limits to the neutrinoless double beta decay are found in the T$_{1/2}^{0\nu}>5.5\times10^{23}-1.3\times10^{24}$ yr range, depending on the method. The presented techniques stand as a proof-of-concept for the searches to be implemented with larger NEXT detectors.
A Compact Dication Source for Ba$^{2+}$ Tagging and Heavy Metal Ion Sensor Development
K.E. Navarro, B.J.P. Jones, J. Baeza-Rubio, M. Boyd, A.A. Denisenko, F.W. Foss, S.Giri, R. Miller, D.R. Nygren, M.R. Tiscareno, F. J. Samaniego, K. Stogsdill, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, S. Ayet, et al (90)
Mar 06 2023 physics.ins-det hep-ex nucl-ex arXiv:2303.01522v1

@misc{2303.01522, author = {K.E.~Navarro and B.J.P.~Jones and J.~Baeza-Rubio and M.~Boyd and A.A.~Denisenko and F.W.~Foss and S.Giri and R.~Miller and D.R.~Nygren and M.R.~Tiscareno and F.~J.~Samaniego and K.~Stogsdill and C.~Adams and H.~Almazán and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and L.~Arazi and I.J.~Arnquist and S.~Ayet and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and S.~Bounasser and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and F.P.~Cossío and E.~Dey and G.~Díaz and T.~Dickel and J.~Escada and R.~Esteve and A.~Fahs and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and Z.~Freixa and J.~Generowicz and A.~Goldschmidt and J.J.~Gómez-Cadenas and R.~González and J.~Grocott and R.~Guenette and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero-Gómez and V.~Herrero and C.~Hervés Carrete and J.~Ho and P.~Ho and Y.~Ifergan and L.~Labarga and L.~Larizgoitia and P.~Lebrun and D.~Lopez Gutierrez and N.~López-March and R.~Madigan and R.D.P.~Mano and A.~P.~Marques and J.~Martín-Albo and G.~Martínez-Lema and M.~Martínez-Vara and Z.E.~Meziani and K.~Mistry and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and P.~Novella and A.~Nuñez and E.~Oblak and M.~Odriozola-Gimeno and B.~Palmeiro and A.~Para and J.~Pelegrín and M.~Pérez Maneiro and M.~Querol and A.B.~Redwine and J.~Renner and I.~Rivilla and J.~Rodríguez and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and M.~Sorel and C.~Stanford and J.M.R.~Teixeira and J.F.~Toledo and J.~Torrent and A.~Usón and J.F.C.A.~Veloso and T.T.~Vuong and J.~Waiton and J.T.~White}, title = {{A} {C}ompact {D}ication {S}ource for {B}a$^{2+}$ {T}agging and {H}eavy {M}etal {I}on {S}ensor {D}evelopment}, year = {2023}, eprint = {2303.01522}, note = {arXiv:2303.01522v1} }
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We present a tunable metal ion beam that delivers controllable ion currents in the picoamp range for testing of dry-phase ion sensors. Ion beams are formed by sequential atomic evaporation and single or multiple electron impact ionization, followed by acceleration into a sensing region. Controllability of the ionic charge state is achieved through tuning of electrode potentials that influence the retention time in the ionization region. Barium, lead, and cobalt samples have been used to test the system, with ion currents identified and quantified using a quadrupole mass analyzer. Realization of a clean $\mathrm{Ba^{2+}}$ ion beam within a bench-top system represents an important technical advance toward the development and characterization of barium tagging systems for neutrinoless double beta decay searches in xenon gas. This system also provides a testbed for investigation of novel ion sensing methodologies for environmental assay applications, with dication beams of Pb$^{2+}$ and Cd$^{2+}$ also demonstrated for this purpose.
Reflectance and fluorescence characteristics of PTFE coated with TPB at visible, UV, and VUV as a function of thickness
J. Haefner, A. Fahs, J. Ho, C. Stanford, R. Guenette, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, F. Auria-Luna, S. Ayet, C.D.R. Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, S. Bounasser, et al (83)
Nov 10 2022 physics.ins-det hep-ex physics.optics arXiv:2211.05024v3

@misc{2211.05024, author = {J.~Haefner and A.~Fahs and J.~Ho and C.~Stanford and R.~Guenette and C.~Adams and H.~Almazán and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and L.~Arazi and I.J.~Arnquist and F.~Auria-Luna and S.~Ayet and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and S.~Bounasser and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and F.P.~Cossío and A.A.~Denisenko and E.~Dey and G.~Díaz and T.~Dickel and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and F.W.~Foss and E.D.C.~Freitas and Z.~Freixa and J.~Generowicz and A.~Goldschmidt and J.J.~Gómez-Cadenas and R.~González and J.~Grocott and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero-Gómez and V.~Herrero and P.~Ho and Y.~Ifergan and B.J.P.~Jones and M.~Kekic and L.~Labarga and L.~Larizgoitia and P.~Lebrun and D.~Lopez Gutierrez and N.~López-March and R.~Madigan and R.D.P.~Mano and J.~Martín-Albo and G.~Martínez-Lema and M.~Martínez-Vara and A.P.~Marques and Z.E.~Meziani and R.~Miller and K.~Mistry and J.~Molina-Canteras and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and K.~Navarro and P.~Novella and A.~Nuñez and D.R.~Nygren and E.~Oblak and M.~Odriozola-Gimeno and B.~Palmeiro and A.~Para and M.~Querol and A.B.~Redwine and J.~Renner and I.~Rivilla and J.~Rodríguez and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and M.~Sorel and J.M.R.~Teixeira and J.F.~Toledo and J.~Torrent and A.~Usón and J.F.C.A.~Veloso and T.T.~Vuong and J.~Waiton}, title = {{R}eflectance and fluorescence characteristics of {PTFE} coated with {TPB} at visible, {UV}, and {VUV} as a function of thickness}, year = {2022}, eprint = {2211.05024}, note = {arXiv:2211.05024v3} }
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Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. In noble element systems, it is often coated with tetraphenyl butadiene (TPB) to allow detection of vacuum ultraviolet scintillation light. In this work this dependence is investigated for PTFE coated with TPB in air for light of wavelengths of 200~nm, 260~nm, and 450~nm. The results show that TPB-coated PTFE has a reflectance of approximately 92\% for thicknesses ranging from 5~mm to 10~mm at 450~nm, with negligible variation as a function of thickness within this range. A cross-check of these results using an argon chamber supports the conclusion that the change in thickness from 5~mm to 10~mm does not affect significantly the light response at 128~nm. Our results indicate that pieces of TPB-coated PTFE thinner than the typical 10~mm can be used in particle physics detectors without compromising the light signal.
Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of $\rho^0$ mesons
G. D. Alexeev, M. G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C. D. R. Azevedo, B. Badelek, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V. E. Burtsev, W.-C. Chang, C. Chatterjee, et al (172)
Nov 02 2022 hep-ex hep-ph arXiv:2211.00093v2

@misc{2211.00093, author = {G.~D.~Alexeev and M.~G.~Alexeev and C.~Alice and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.~D.~R.~Azevedo and B.~Badelek and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.~E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.~G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.~M.~M.~Correia and M.~L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.~S.~Dasgupta and S.~Dasgupta and F.~Del Carro and I.~Denisenko and O.~Yu.~Denisov and S.~V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Dünnweber and R.~R.~Dusaev and D.~Ecker and A.~Efremov and C.~Elia and D.~Eremeev and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~J.~Flöthner and W.~Florian and J.~M.~Friedrich and V.~Frolov and L.G.~Garcia Ordòñez and F.~Gautheron and O.~P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and M.~Grüner and A.~Guskov and D.~von Harrach and M.~Hoffmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and V.~Jary and R.~Joosten and E.~Kabuß and F.~Kaspar and A.~Kerbizi and B.~Ketzer and A.~Khatun and G.~V.~Khaustov and F.~Klein and J.~H.~Koivuniemi and V.~N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and V.~F.~Konstantinov and A.~M.~Korzenev and A.~M.~Kotzinian and O.~M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and F.~Kunne and K.~Kurek and R.~P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.~E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.~K.~Mallot and A.~Maltsev and S.~A.~Mamon and A.~Martin and J.~Marzec and J.~Matoušek and T.~Matsuda and G.~Mattson and C.~Menezes Pires and F.~Metzger and M.~Meyer and W.~Meyer and Yu.~V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and D.~Miura and Y.~Miyachi and R.~Molina and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Nový and W.-D.~Nowak and G.~Nukazuka and A.~G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pešek and D.~V.~Peshekhonov and M.~Pešková and S.~Platchkov and J.~Pochodzalla and V.~A.~Polyakov and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.~I.~Ryabchikov and A.~Rychter and A.~Rymbekova and V.~D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.~A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and M.~Slunecka and F.~Sozzi and D.~Spülbeck and A.~Srnka and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and T.~Triloki and V.~Tskhay and B.~Valinoti and B.~M.~Veit and J.F.C.A.~Veloso and B.~Ventura and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and M.~Ziembicki}, title = {{C}ollins and {S}ivers transverse-spin asymmetries in inclusive muoproduction of $\rho^0$ mesons}, year = {2022}, eprint = {2211.00093}, note = {arXiv:2211.00093v2} }
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The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced $\rho^0$ mesons. The analysis is based on the data set collected in deep inelastic scattering in $2010$ using a $160\,\,\rm{GeV}/c$ $\mu^+$ beam impinging on a transversely polarized $\rm{NH}_3$ target. The $\rho^{0}$ mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-$x$ variable, the transverse momentum of the pair and the fraction of the energy $z$ carried by the pair. Indications for positive Collins and Sivers asymmetries are observed.
Spin Density Matrix Elements in Exclusive $\rho ^0$ Meson Muoproduction
G. D. Alexeev, M. G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C. D. R. Azevedo, B. Badelek, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V. E. Burtsev, W.-C. Chang, C. Chatterjee, et al (170)
Nov 01 2022 hep-ex hep-ph arXiv:2210.16932v2

@misc{2210.16932, author = {G.~D.~Alexeev and M.~G.~Alexeev and C.~Alice and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.~D.~R.~Azevedo and B.~Badelek and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.~E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.~G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.~M.~M.~Correia and M.~L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.~S.~Dasgupta and S.~Dasgupta and F.~Del Carro and I.~Denisenko and O.~Yu.~Denisov and S.~V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Dünnweber and R.~R.~Dusaev and D.~Ecker and A.~Efremov and D.~Eremeev and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~J.~Flöthner and W.~Florian and J.~M.~Friedrich and V.~Frolov and L.G.~Garcia Ordòñez and F.~Gautheron and O.~P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and M.~Grüner and A.~Guskov and D.~von Harrach and M.~Hoffmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and V.~Jary and R.~Joosten and E.~Kabuß and F.~Kaspar and A.~Kerbizi and B.~Ketzer and A.~Khatun and G.~V.~Khaustov and F.~Klein and J.~H.~Koivuniemi and V.~N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and V.~F.~Konstantinov and A.~M.~Korzenev and A.~M.~Kotzinian and O.~M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and F.~Kunne and K.~Kurek and R.~P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.~E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.~K.~Mallot and A.~Maltsev and S.~A.~Mamon and A.~Martin and J.~Marzec and J.~Matoušek and T.~Matsuda and G.~Mattson and C.~Menezes Pires and F.~Metzger and M.~Meyer and W.~Meyer and Yu.~V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and D.~Miura and Y.~Miyachi and R.~Molina and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and M.~Niemiec and J.~Nový and W.-D.~Nowak and G.~Nukazuka and A.~G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pešek and D.~V.~Peshekhonov and M.~Pešková and S.~Platchkov and J.~Pochodzalla and V.~A.~Polyakov and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and D.~I.~Ryabchikov and A.~Rychter and A.~Rymbekova and V.~D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.~A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and M.~Slunecka and D.~Spülbeck and A.~Srnka and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and T.~Triloki and V.~Tskhay and B.~Valinoti and B.~M.~Veit and J.F.C.A.~Veloso and B.~Ventura and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and M.~Ziembicki}, title = {{S}pin {D}ensity {M}atrix {E}lements in {E}xclusive $\rho ^0$ {M}eson {M}uoproduction}, year = {2022}, eprint = {2210.16932}, note = {arXiv:2210.16932v2} }
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We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $\rho ^0$ meson muoproduction at COMPASS using 160~GeV/$c$ polarised $ \mu ^{+}$ and $ \mu ^{-}$ beams impinging on a liquid hydrogen target. The measurement covers the kinematic range 5.0~GeV/$c^2$ $< W <$ 17.0~GeV/$c^2$, 1.0 (GeV/$c$)$^2$ $< Q^2 <$ 10.0 (GeV/$c$)$^2$ and 0.01 (GeV/$c$)$^2$ $< p_{\rm{T}}^2 <$ 0.5 (GeV/$c$)$^2$. Here, $W$ denotes the mass of the final hadronic system, $Q^2$ the virtuality of the exchanged photon, and $p_{\rm{T}}$ the transverse momentum of the $\rho ^0$ meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons ($\gamma^*_T \to V^{ }_L$) indicate a violation of $s$-channel helicity conservation. Additionally, we observe a dominant contribution of natural-parity-exchange transitions and a very small contribution of unnatural-parity-exchange transitions, which is compatible with zero within experimental uncertainties. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow one to evaluate in a model-dependent way the role of parton helicity-flip GPDs in exclusive $\rho ^0$ production.
Test-Beam and Simulation Studies Towards RPWELL-based DHCAL
Dan Shaked-Renous, Fernando Domingues Amaro, Purba Bhattacharya, Amos Breskin, Maximilien Chefdeville, Cyril Drancourt, Theo Geralis, Yannis Karyotakis, Luca Moleri, Andrea Tesi, Maxim Titov, Joao Veloso, Guillaum Vouters, Shikma Bressler
Aug 30 2022 physics.ins-det hep-ex arXiv:2208.12846v3

@misc{2208.12846, author = {Dan Shaked-Renous and Fernando Domingues Amaro and Purba Bhattacharya and Amos Breskin and Maximilien Chefdeville and Cyril Drancourt and Theo Geralis and Yannis Karyotakis and Luca Moleri and Andrea Tesi and Maxim Titov and Joao Veloso and Guillaum Vouters and Shikma Bressler}, title = {{T}est-{B}eam and {S}imulation {S}tudies {T}owards {RPWELL}-based {DHCAL}}, year = {2022}, eprint = {2208.12846}, note = {arXiv:2208.12846v3} }
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Digital Hadronic Calorimeters (DHCAL) were suggested for future Colliders as part of the particle-flow concept. Though studied mainly with Resistive Plate Chambers (RPC), studies focusing on Micro-Pattern Gaseous Detector (MPGD)-based sampling elements have shown the potential advantages; they can be operated with environmental friendly gases and reach similar detection efficiency at lower average pad-multiplicity. We summarize here the experimental test-beam results of a small-size DHCAL prototype, incorporating six Micromegas (MM) and two Resistive-Plate WELL (RPWELL) sampling elements, interlaced with steel-absorber plates. It was investigated with 2-6 GeV pion beam at the CERN/PS beam facility. The data permitted validating a GEANT4 simulation framework of a DHCAL, and evaluating the expected pion energy resolution of a full-scale RPWELL-based calorimeter. The pion energy resolution of $\frac{\sigma}{E[GeV]}=\frac{50.8\%}{\sqrt{E[GeV]}} \oplus 10.3\%$ derived expected with the RPWELL concept is competitive to that of glass RPC and MM sampling techniques.
Double $J/\psi$ production in pion-nucleon scattering at COMPASS
G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V.E. Burtsev, W.-C. Chang, C. Chatterjee, et al (175)
Apr 06 2022 hep-ex hep-ph arXiv:2204.01817v1

@misc{2204.01817, author = {G.D.~Alexeev and M.G.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and D.~Eremeev and P.D.~Eversheim and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~Floethner and W Florian and C.~Franco and J.M.~Friedrich and V.~Frolov and L.G.~Garcia Ordonez and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and M.~Gorzellik and A.~Grasso and A.~Gridin and S.~Groote and M.~Grosse Perdekamp and B.~Grube and M.~Gruener and A.~Guskov and D.~von Harrach and M.~Hoffmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and A.~Khatun and G.V.~Khaustov and Yu.A.~Khokhlov and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and V.F.~Konstantinov and A.~Korzenev and S.~Koshkarev and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and C.~Menezes Pires and F.~Metzger and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and Y.~Miyachi and R.~Molina and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.I.~Ryabchikov and A.~Rychter and A.~Rymbekova and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and S.~Schmeing and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and M.~Slunecka and D.~Spuelbeck and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and T.~Triloki and V.~Tskhaty and B.~Valinoti and B.M.~Veit and J.~F.~C.~A.~Veloso and B.~Ventura and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and M.~Ziembicki}, title = {{D}ouble ${J}/\psi$ production in pion-nucleon scattering at {COMPASS}}, year = {2022}, eprint = {2204.01817}, note = {arXiv:2204.01817v1} }
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We present the study of the production of double $J/\psi$ mesons using COMPASS data collected with a 190 GeV/$c$ $\pi^-$ beam scattering off NH$_{3}$, Al and W targets. Kinematic distributions of the collected double $J/\psi$ events are analysed, and the double $J/\psi$ production cross section is estimated for each of the COMPASS targets. The results are compared to predictions from single- and double-parton scattering models as well as the pion intrinsic charm and the tetraquark exotic resonance hypotheses. It is demonstrated that the single parton scattering production mechanism gives the dominant contribution that is sufficient to describe the data. An upper limit on the double intrinsic charm content of pion is evaluated. No significant signatures that could be associated with exotic tetraquarks are found in the double $J/\psi$ mass spectrum.
Ba$^{2+}$ ion trapping by organic submonolayer: towards an ultra-low background neutrinoless double beta decay detector
P. Herrero-Gómez, J.P. Calupitan, M. Ilyn, A. Berdonces-Layunta, T. Wang, D.G. de Oteyza, M. Corso, R. González-Moreno, I. Rivilla, B. Aparicio, A.I. Aranburu, Z. Freixa, F. Monrabal, F.P. Cossío, J.J. Gómez-Cadenas, C. Rogero, C. Adams, H. Almazán, V. Alvarez, L. Arazi, et al (95)
Jan 25 2022 hep-ex cond-mat.mtrl-sci physics.chem-ph arXiv:2201.09099v1

@misc{2201.09099, author = {P.~Herrero-Gómez and J.P.~Calupitan and M.~Ilyn and A.~Berdonces-Layunta and T.~Wang and D.G.~de Oteyza and M.~Corso and R.~González-Moreno and I.~Rivilla and B.~Aparicio and A.I.~Aranburu and Z.~Freixa and F.~Monrabal and F.P.~Cossío and J.J.~Gómez-Cadenas and C.~Rogero and C.~Adams and H.~Almazán and V.~Alvarez and L.~Arazi and I.J.~Arnquist and S.~Ayet and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and S.~Bounasser and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and A.A.~Denisenko and G.~Díaz and J.~Díaz and T.~Dickel and J.~Escada and R.~Esteve and A.~Fahs and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and F.W.~Foss and E.D.C.~Freitas and J.~Generowicz and A.~Goldschmidt and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and V.~Herrero and J.~Ho and Y.~Ifergan and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and L.~Larizgoitia and P.~Lebrun and D.~Lopez Gutierrez and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and G.~Martínez-Lema and M.~Martínez-Vara and A.D.~McDonald and Z.E.~Meziani and K.~Mistry and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and K.~Navarro and P.~Novella and D.R.~Nygren and E.~Oblak and M.~Odriozola-Gimeno and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and A.~Raymond and A.B.~Redwine and J.~Renner and L.~Ripoll and Y.~Rodríguez García and J.~Rodríguez and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.dos Santos and A.~Simón and M.~Sorel and C.~Stanford and J.M.R.~Teixeira and P.~Thapa and J.F.~Toledo and J.~Torrent and A.~Usón and J.F.C.A.~Veloso and T.T.~Vuong and R.~Webb and J.T.~White and K.~Woodruff and N.~Yahlali}, title = {{B}a$^{2+}$ ion trapping by organic submonolayer: towards an ultra-low background neutrinoless double beta decay detector}, year = {2022}, eprint = {2201.09099}, note = {arXiv:2201.09099v1} }
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If neutrinos are their own antiparticles, the otherwise-forbidden nuclear reaction known as neutrinoless double beta decay ($\beta\beta 0\nu$) can occur, with a characteristic lifetime which is expected to be very long, making the suppression of backgrounds a daunting task. It has been shown that detecting (``tagging'') the Ba$^{+2}$ dication produced in the double beta decay ${}^{136}\mathrm{Xe} \rightarrow {}^{136}$Ba$^{+2}+ 2 e + (2 \nu)$ in a high pressure gas experiment, could lead to a virtually background free experiment. To identify these \Bapp, chemical sensors are being explored as a key tool by the NEXT collaboration . Although used in many fields, the application of such chemosensors to the field of particle physics is totally novel and requires experimental demonstration of their suitability in the ultra-dry environment of a xenon gas chamber. Here we use a combination of complementary surface science techniques to unambiguously show that Ba$^{+2}$ ions can be trapped (chelated) in vacuum by an organic molecule, the so-called fluorescent bicolour indicator (FBI) (one of the chemosensors developed by NEXT), immobilized on a surface. We unravel the ion capture mechanism once the molecules are immobilised on Au(111) surface and explain the origin of the emission fluorescence shift associated to the trapping of different ions. Moreover, we prove that chelation also takes place on a technologically relevant substrate, as such, demonstrating the feasibility of using FBI indicators as building blocks of a Ba$^{+2}$ detector.
Measurement of the ${}^{136}$Xe two-neutrino double beta decay half-life via direct background subtraction in NEXT
NEXT Collaboration, P. Novella, M. Sorel, A. Usón, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, L. Arazi, I.J. Arnquist, S. Ayet, C.D.R. Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, S. Bounasser, N. Byrnes, S. Cárcel, et al (90)
Nov 23 2021 nucl-ex hep-ex physics.ins-det arXiv:2111.11091v3

@misc{2111.11091, author = {NEXT Collaboration and P.~Novella and M.~Sorel and A.~Usón and C.~Adams and H.~Almazán and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and L.~Arazi and I.J.~Arnquist and S.~Ayet and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and S.~Bounasser and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and F.P.~Cossío and A.A.~Denisenko and G.~Díaz and J.~Díaz and T.~Dickel and J.~Escada and R.~Esteve and A.~Fahs and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and F.W.~Foss and E.D.C.~Freitas and Z.~Freixa and J.~Generowicz and A.~Goldschmidt and J.J.~Gómez-Cadenas and R.~González and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero-Gómez and V.~Herrero and J.~Ho and Y.~Ifergan and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and L.~Larizgoitia and P.~Lebrun and D.~Lopez Gutierrez and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and G.~Martínez-Lema and M.~Martínez-Vara and A.D.~McDonald and Z.E.~Meziani and K.~Mistry and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and K.~Navarro and D.R.~Nygren and E.~Oblak and M.~Odriozola-Gimeno and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and A.~Raymond and A.B.~Redwine and J.~Renner and L.~Ripoll and I.~Rivilla and Y.~Rodríguez García and J.~Rodríguez and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Stanford and J.M.R.~Teixeira and P.~Thapa and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and T.T.~Vuong and R.~Webb and J.T.~White and K.~Woodruff and N.~Yahlali}, title = {{M}easurement of the ${}^{136}${X}e two-neutrino double beta decay half-life via direct background subtraction in {NEXT}}, year = {2021}, eprint = {2111.11091}, howpublished = {Phys. Rev. C 105, 055501 (2022)}, doi = {10.1103/PhysRevC.105.055501}, note = {arXiv:2111.11091v3} }
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We report a measurement of the half-life of the ${}^{136}$Xe two-neutrino double beta decay performed with a novel direct background subtraction technique. The analysis relies on the data collected with the NEXT-White detector operated with ${}^{136}$Xe-enriched and ${}^{136}$Xe-depleted xenon, as well as on the topology of double-electron tracks. With a fiducial mass of only 3.5 kg of Xe, a half-life of $2.34^{+0.80}_{-0.46}\textrm{(stat)}^{+0.30}_{-0.17}\textrm{(sys)}\times10^{21}~\textrm{yr}$ is derived from the background-subtracted energy spectrum. The presented technique demonstrates the feasibility of unique background-model-independent neutrinoless double beta decay searches.
The exotic meson $\pi_1(1600)$ with $J^{PC} = 1^{-+}$ and its decay into $\rho(770)\pi$
M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V.E. Burtsev, et al (176)
Aug 05 2021 hep-ex hep-ph arXiv:2108.01744v2

@misc{2108.01744, author = {M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Berenguer Antequera and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and D.~Eremeev and P.D.~Eversheim and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and K.~Floethner and C.~Franco and J.M.~Friedrich and V.~Frolov and L.G.~Garcia Ordonez and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and D.~Giordano and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and F.~Haas and D.~von Harrach and M.~Hoffmann and R.~Heitz and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and F.~Metzger and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.G.~Olshevsky and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.I.~Ryabchikov and A.~Rymbekova and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and S.~Schmeing and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and M.~Slunecka and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and V.~Tskhay and T.~Triloki and S.~Uhl and A.~Vauth and B.M.~Veit and J.~Veloso and B.~Ventura and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{T}he exotic meson $\pi_1(1600)$ with ${J}^{{PC}} = 1^{-+}$ and its decay into $\rho(770)\pi$}, year = {2021}, eprint = {2108.01744}, howpublished = {Phys.Rev.D 105 (2022) 1, 012005}, doi = {10.1103/PhysRevD.105.012005}, note = {arXiv:2108.01744v2} }
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We study the spin-exotic $J^{PC} = 1^{-+}$ amplitude in single-diffractive dissociation of 190 GeV$/c$ pions into $\pi^-\pi^-\pi^+$ using a hydrogen target and confirm the $\pi_1(1600) \to \rho(770) \pi$ amplitude, which interferes with a nonresonant $1^{-+}$ amplitude. We demonstrate that conflicting conclusions from previous studies on these amplitudes can be attributed to different analysis models and different treatment of the dependence of the amplitudes on the squared four-momentum transfer and we thus reconcile their experimental findings. We study the nonresonant contributions to the $\pi^-\pi^-\pi^+$ final state using pseudo-data generated on the basis of a Deck model. Subjecting pseudo-data and real data to the same partial-wave analysis, we find good agreement concerning the spectral shape and its dependence on the squared four-momentum transfer for the $J^{PC} = 1^{-+}$ amplitude and also for amplitudes with other $J^{PC}$ quantum numbers. We investigate for the first time the amplitude of the $\pi^-\pi^+$ subsystem with $J^{PC} = 1^{--}$ in the $3\pi$ amplitude with $J^{PC} = 1^{-+}$ employing the novel freed-isobar analysis scheme. We reveal this $\pi^-\pi^+$ amplitude to be dominated by the $\rho(770)$ for both the $\pi_1(1600)$ and the nonresonant contribution. We determine the $\rho(770)$ resonance parameters within the three-pion final state. These findings largely confirm the underlying assumptions for the isobar model used in all previous partial-wave analyses addressing the $J^{PC} = 1^{-+}$ amplitude.
Probing transversity by measuring $\Lambda$ polarisation in SIDIS
M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V.E. Burtsev, et al (180)
Apr 29 2021 hep-ex arXiv:2104.13585v2

@misc{2104.13585, author = {M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Berenguer Antequera and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and P.D.~Eversheim and P.~Faccioli and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and J.M.~Friedrich and V.~Frolov and L.G.~Garcia Ordonez and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and D.~Giordano and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~von Harrach and R.~Heitz and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and E.~Kabuss and D.H.~Kang and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.~Naim and T.S.~Negrini and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.I.~Ryabchikov and A.~Rymbekova and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and P.~Schiavon and H.~Schmieden and A.~Selyunin and K.~Sharko and L.~Sinha and M.~Slunecka and J.~Smolik and F.~Sozzi and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and P.~Sznajder and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and V.~Tskhay and S.~Uhl and A.~Vauth and B.M.~Veit and J.~Veloso and B.~Ventura and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and P.~Zavada and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{P}robing transversity by measuring $\{L}ambda$ polarisation in {SIDIS}}, year = {2021}, eprint = {2104.13585}, note = {arXiv:2104.13585v2} }
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Based on the observation of sizeable target-transverse-spin asymmetries in single-hadron and hadron-pair production in Semi-Inclusive measurements of Deep Inelastic Scattering (SIDIS), the chiral-odd transversity quark distribution functions $h_1^q$ are nowadays well established. Several possible channels to access these functions were originally proposed. One candidate is the measurement of the polarisation of $\Lambda$ hyperons produced in SIDIS off transversely polarised nucleons, where the transverse polarisation of the struck quark might be transferred to the final-state hyperon. In this article, we present the COMPASS results on the transversity-induced polarisation of $\Lambda$ and $\bar{\Lambda}$ hyperons produced in SIDIS off transversely polarised protons. Within the experimental uncertainties, no significant deviation from zero was observed. The results are discussed in the context of different models taking into account previous experimental results on $h_1^u$ and $h_1^d$.
Boosting background suppression in the NEXT experiment through Richardson-Lucy deconvolution
A. Simón, Y. Ifergan, A.B. Redwine, R. Weiss-Babai, L. Arazi, C. Adams, H. Almazán, V. Álvarez, B. Aparicio, A.I. Aranburu, I.J. Arnquist, C.D.R Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, N. Byrnes, S. Cárcel, J.V. Carrión, S. Cebrián, et al (83)
Feb 25 2021 physics.ins-det hep-ex arXiv:2102.11931v3

@misc{2102.11931, author = {A.~Simón and Y.~Ifergan and A.B.~Redwine and R.~Weiss-Babai and L.~Arazi and C.~Adams and H.~Almazán and V.~Álvarez and B.~Aparicio and A.I.~Aranburu and I.J.~Arnquist and C.D.R Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and F.P.~Cossío and A.A.~Denisenko and G.~Díaz and J.~Díaz and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and F.~Foss and E.D.C.~Freitas and Z.~Freixa and J.~Generowicz and A.~Goldschmidt and J.J.~Gómez-Cadenas and R.~González and D.~González-Díaz and S.~Gosh and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero and V.~Herrero and J.~Ho and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and M.~Martínez-Vara and G.~Martínez-Lema and A.D.~McDonald and Z.-E.~Meziani and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and C.~Newhouse and P.~Novella and D.R.~Nygren and E.~Oblak and M.~Odriozola-Gimeno and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and J.~Renner and L.~Ripoll and I.~Rivilla and Y.~Rodríguez García and J.~Rodríguez and C.~Rogero and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and M.~Sorel and C.~Stanford and J.M.R.~Teixeira and P.~Thapa and J.F.~Toledo and J.~Torrent and A.~Usón and J.F.C.A.~Veloso and T.T.~Vuong and R.~Webb and J.T.~White and K.~Woodruff and N.~Yahlali}, title = {{B}oosting background suppression in the {NEXT} experiment through {R}ichardson-{L}ucy deconvolution}, year = {2021}, eprint = {2102.11931}, note = {arXiv:2102.11931v3} }
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Next-generation neutrinoless double beta decay experiments aim for half-life sensitivities of ~$10^{27}$ yr, requiring suppressing backgrounds to <1 count/tonne/yr. For this, any extra background rejection handle, beyond excellent energy resolution and the use of extremely radiopure materials, is of utmost importance. The NEXT experiment exploits differences in the spatial ionization patterns of double beta decay and single-electron events to discriminate signal from background. While the former display two Bragg peak dense ionization regions at the opposite ends of the track, the latter typically have only one such feature. Thus, comparing the energies at the track extremes provides an additional rejection tool. The unique combination of the topology-based background discrimination and excellent energy resolution (1% FWHM at the Q-value of the decay) is the distinguishing feature of NEXT. Previous studies demonstrated a topological background rejection factor of ~5 when reconstructing electron-positron pairs in the $^{208}$Tl 1.6 MeV double escape peak (with Compton events as background), recorded in the NEXT-White demonstrator at the Laboratorio Subterráneo de Canfranc, with 72% signal efficiency. This was recently improved through the use of a deep convolutional neural network to yield a background rejection factor of ~10 with 65% signal efficiency. Here, we present a new reconstruction method, based on the Richardson-Lucy deconvolution algorithm, which allows reversing the blurring induced by electron diffusion and electroluminescence light production in the NEXT TPC. The new method yields highly refined 3D images of reconstructed events, and, as a result, significantly improves the topological background discrimination. When applied to real-data 1.6 MeV $e^-e^+$ pairs, it leads to a background rejection factor of 27 at 57% signal efficiency.
Demonstration of background rejection using deep convolutional neural networks in the NEXT experiment
NEXT Collaboration, M. Kekic, C. Adams, K. Woodruff, J. Renner, E. Church, M. Del Tutto, J.A. Hernando Morata, J.J. Gomez-Cadenas, V. Alvarez, L. Arazi, I.J. Arnquist, C.D.R Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodriguez, F.I.G.M. Borges, N. Byrnes, S. Carcel, J.V. Carrion, et al (71)
Sep 24 2020 physics.ins-det hep-ex arXiv:2009.10783v2

@misc{2009.10783, author = {NEXT Collaboration and M.~Kekic and C.~Adams and K.~Woodruff and J.~Renner and E.~Church and M.~Del Tutto and J.A.~Hernando Morata and J.J.~Gomez-Cadenas and V.~Alvarez and L.~Arazi and I.J.~Arnquist and C.D.R Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodriguez and F.I.G.M.~Borges and N.~Byrnes and S.~Carcel and J.V.~Carrion and S.~Cebrian and C.A.N.~Conde and T.~Contreras and G.~Diaz and J.~Diaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and A.F.M.~Fernandes and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and S.~Ghosh and A.~Goldschmidt and D.~Gonzalez-Diaz and R.~Guenette and R.M.~Gutierrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and P.~Herrero and V.~Herrero and Y.~Ifergan and B.J.P.~Jones and L.~Labarga and A.~Laing and P.~Lebrun and N.~Lopez-March and M.~Losada and R.D.P.~Mano and J.~Martin-Albo and A.~Martinez and G.~Martinez-Lema and M.~Martinez-Vara and A.D.~McDonald and Z.~E.~Meziani and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Perez and M.~Querol and A.B.~Redwine and L.~Ripoll and Y.~Rodriguez Garcia and J.~Rodriguez and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simon and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and A.~Uson and J.F.C.A.~Veloso and R.~Webb and R.~Weiss-Babai and J.T.~White and N.~Yahlali}, title = {{D}emonstration of background rejection using deep convolutional neural networks in the {NEXT} experiment}, year = {2020}, eprint = {2009.10783}, doi = {10.1007/JHEP01(2021)189}, note = {arXiv:2009.10783v2} }
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Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in $^{136}$Xe. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6-MeV gamma rays from a $^{228}$Th calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offer significant improvement in signal efficiency/background rejection when compared to previous non-CNN-based analyses.
Spin Density Matrix Elements in Exclusive $\omega$ Meson Muoproduction $^*$
M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, et al (181)
Sep 08 2020 hep-ex arXiv:2009.03271v3

@misc{2009.03271, author = {M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Berenguer Antequera and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and P.D.~Eversheim and P.~Faccioli and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and J.M.~Friedrich and V.~Frolov and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo Horikawa and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and C.~Regali and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and L.~Sinha and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and T.~Szameitat and P.~Sznajder and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and B.~Ventura and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and P.~Zavada and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{S}pin {D}ensity {M}atrix {E}lements in {E}xclusive $\omega$ {M}eson {M}uoproduction $^*$}, year = {2020}, eprint = {2009.03271}, note = {arXiv:2009.03271v3} }
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We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $\omega$ meson muoproduction on the proton at COMPASS using 160 GeV/$c$ polarised $ \mu ^{+}$ and $ \mu ^{-}$ beams impinging on a liquid hydrogen target. The measurement covers the range 5.0 GeV/$c^2$ $< W <$ 17.0 GeV/$c^2$, with the average kinematics $\langle Q^{2} \rangle=$ 2.1 (GeV/$c$)$^2$, $\langle W \rangle= 7.6$ GeV/$c^2$, and $\langle p^{2}_{\rm T} \rangle = 0.16$ (GeV/$c$)$^2$. Here, $Q^2$ denotes the virtuality of the exchanged photon, $W$ the mass of the final hadronic system and $p_T$ the transverse momentum of the $\omega$ meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons ($\gamma^*_T \to V_L$) indicate a violation of $s$-channel helicity conservation. Additionally, we observe a sizeable contribution of unnatural-parity-exchange (UPE) transitions that decreases with increasing $W$. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow to evaluate in a model-dependent way the contribution of UPE transitions and assess the role of parton helicity-flip GPDs in exclusive $\omega$ production.
Sensitivity of the NEXT experiment to Xe-124 double electron capture
G. Martínez-Lema, M. Martínez-Vara, M. Sorel, C. Adams, V. Alvarez, L. Arazi, I.J. Arnquist, C.D.R Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, N. Byrnes, S. Cárcel, J.V. Carrión, S. Cebrián, E. Church, C.A.N. Conde, T. Contreras, G. Díaz, et al (71)
Jun 15 2020 hep-ex nucl-ex physics.ins-det arXiv:2006.07320v3

@misc{2006.07320, author = {G.~Martínez-Lema and M.~Martínez-Vara and M.~Sorel and C.~Adams and V.~Alvarez and L.~Arazi and I.J.~Arnquist and C.D.R Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and G.~Díaz and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and A.F.M.~Fernandes and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and S.~Ghosh and A.~Goldschmidt and J.J.~Gómez-Cadenas and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero and V.~Herrero and Y.~Ifergan and S.~Johnston and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and A.D.~McDonald and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and A.B.~Redwine and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and Y.~Rodríguez García and J.~Rodríguez and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and T.~Stiegler and J.F.~Toledo and J.~Torrent and A.~Usón and J.F.C.A.~Veloso and R.~Webb and R.~Weiss-Babai and J.T.~White and K.~Woodruff and N.~Yahlali}, title = {{S}ensitivity of the {NEXT} experiment to {X}e-124 double electron capture}, year = {2020}, eprint = {2006.07320}, howpublished = {J. High Energ. Phys. 2021, 203 (2021)}, doi = {10.1007/JHEP02(2021)203}, note = {arXiv:2006.07320v3} }
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Double electron capture by proton-rich nuclei is a second-order nuclear process analogous to double beta decay. Despite their similarities, the decay signature is quite different, potentially providing a new channel to measure the hypothesized neutrinoless mode of these decays. The Standard-Model-allowed two-neutrino double electron capture ($2\nu ECEC$) has been predicted for a number of isotopes, but only observed in $^{78}$Kr, $^{130}$Ba and, recently, $^{124}$Xe. The sensitivity to this decay establishes a benchmark for the ultimate experimental goal, namely the potential to discover also the lepton-number-violating neutrinoless version of this process, $0\nu ECEC$. Here we report on the current sensitivity of the NEXT-White detector to $^{124}$Xe $2\nu ECEC$ and on the extrapolation to NEXT-100. Using simulated data for the $2\nu ECEC$ signal and real data from NEXT-White operated with $^{124}$Xe-depleted gas as background, we define an optimal event selection that maximizes the NEXT-White sensitivity. We estimate that, for NEXT-100 operated with xenon gas isotopically enriched with 1 kg of $^{124}$Xe and for a 5-year run, a sensitivity to the $2\nu ECEC$ half-life of $6 \times 10^{22}$ y (at 90% confidence level) or better can be reached.
Triangle Singularity as the Origin of the $a_1(1420)$
G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, et al (178)
Jun 11 2020 hep-ph hep-ex arXiv:2006.05342v3

@misc{2006.05342, author = {G.D.~Alexeev and M.G.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Berenguer Antequera and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and P.D.~Eversheim and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and J.M.~Friedrich and V.~Frolov and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and L.~Sinha and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and P.~Sznajder and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and B.~Ventura and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and P.~Zavada and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{T}riangle {S}ingularity as the {O}rigin of the $a_1(1420)$}, year = {2020}, eprint = {2006.05342}, howpublished = {Phys. Rev. Lett. 127, 082501 (2021)}, doi = {10.1103/PhysRevLett.127.082501}, note = {arXiv:2006.05342v3} }
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The COMPASS experiment recently discovered a new isovector resonance-like signal with axial-vector quantum numbers, the $a_1(1420)$, decaying to $f_0(980)\pi$. With a mass too close to and a width smaller than the axial-vector ground state $a_1(1260)$, it was immediately interpreted as a new light exotic meson, similar to the $X$, $Y$, $Z$ states in the hidden-charm sector. We show that a resonance-like signal fully matching the experimental data is produced by the decay of the $a_1(1260)$ resonance into $K^\ast(\to K\pi)\bar{K}$ and subsequent rescattering through a triangle singularity into the coupled $f_0(980)\pi$ channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having less parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonance-like structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.
Antiproton over proton and K$^-$ over K$^+$ multiplicity ratios at high $z$ in DIS
M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, et al (179)
Mar 27 2020 hep-ex arXiv:2003.11791v1

@misc{2003.11791, author = {M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Berenguer Antequera and J.~Bernhard and M.~Bodlak and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and P.D.~Eversheim and P.~Faccioli and M.~Faessler and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and J.M.~Friedrich and V.~Frolov and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and G.~Reicherz and C.~Riedl and T.~Rudnicki and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and L.~Sinha and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and P.~Sznajder and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and B.~Ventura and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and K.~Zaremba and P.~Zavada and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{A}ntiproton over proton and {K}$^-$ over {K}$^+$ multiplicity ratios at high $z$ in {DIS}}, year = {2020}, eprint = {2003.11791}, note = {arXiv:2003.11791v1} }
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The $\bar{\rm p} $ over p multiplicity ratio is measured in deep-inelastic scattering for the first time using (anti-) protons carrying a large fraction of the virtual-photon energy, $z>0.5$. The data were obtained by the COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2$ > 1 (GeV/$c$)$^2$ for the photon virtuality and $W > 5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. The range in Bjorken-$x$ is restricted to $0.01 < x < 0.40$. Protons and antiprotons are identified in the momentum range $20 \div 60$ GeV/$c$. In the whole studied $z$-region, the $\bar{\rm p}$ over p multiplicity ratio is found to be below the lower limit expected from calculations based on leading-order perturbative Quantum Chromodynamics (pQCD). Extending our earlier analysis of the K$^-$ over K$^+$ multiplicity ratio by including now events with larger virtual-photon energies, this ratio becomes closer to the expectation of next-to-leading order pQCD. The results of both analyses strengthen our earlier conclusion that the phase space available for hadronisation should be taken into account in the pQCD formalism.
Mitigation of Backgrounds from Cosmogenic $^{137}$Xe in Xenon Gas Experiments using $^{3}$He Neutron Capture
L. Rogers, B.J.P. Jones, A. Laing, S. Pingulkar, K. Woodruff, C. Adams, V. Álvarez, L. Arazi, I.J. Arnquist, C.D.R Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, N. Byrnes, S. Cárcel, J.V. Carrión, S. Cebrián, E. Church, C.A.N. Conde, et al (72)
Jan 31 2020 physics.ins-det hep-ex arXiv:2001.11147v2

@misc{2001.11147, author = {L.~Rogers and B.J.P.~Jones and A.~Laing and S.~Pingulkar and K.~Woodruff and C.~Adams and V.~Álvarez and L.~Arazi and I.J.~Arnquist and C.D.R Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and G.~Díaz and J.~Díaz and M.~Diesburg and R.~Dingler and J.~Escada and R.~Esteve and R.~Felkai and A.F.M.~Fernandes and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and S.~Ghosh and A.~Goldschmidt and J.J.~Gómez-Cadenas and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero and V.~Herrero and Y.~Ifergan and S.~Johnston and M.~Kekic and L.~Labarga and P.~Lebrun and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and G.~Martínez-Lema and A.D.~McDonald and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and A.B.~Redwine and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and Y.~Rodríguez García and J.~Rodríguez and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and A.~Usón and J.F.C.A.~Veloso and R.~Webb and R.~Weiss-Babai and J.T.~White and N.~Yahlali}, title = {{M}itigation of {B}ackgrounds from {C}osmogenic $^{137}${X}e in {X}enon {G}as {E}xperiments using $^{3}${H}e {N}eutron {C}apture}, year = {2020}, eprint = {2001.11147}, note = {arXiv:2001.11147v2} }
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\Xe136 is used as the target medium for many experiments searching for \bbnonu. Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of \Xe137 created by the capture of neutrons on \Xe136. This isotope decays via beta decay with a half-life of 3.8 minutes and a \Qb of $\sim$4.16 MeV. This work proposes and explores the concept of adding a small percentage of \He3 to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we find the contamination from \Xe137 activation can be reduced to negligible levels in tonne and multi-tonne scale high pressure gas xenon neutrinoless double beta decay experiments running at any depth in an underground laboratory.
Contribution of exclusive diffractive processes to the measured azimuthal asymmetries in SIDIS
J. Agarwala, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, et al (187)
Dec 24 2019 hep-ex arXiv:1912.10322v1

@misc{1912.10322, author = {J.~Agarwala and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Berenguer Antequera and J.~Bernhard and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.M.M.~Correia and M.L.~Crespo and D.~D'Ago and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and I.~Denisenko and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and J.M.~Friedrich and V.~Frolov and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and K.~Lavickova and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.~Mattson and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.~Naim and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and H.~Pekeler and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and G.~Reicherz and C.~Riedl and D.I.~Ryabchikov and T.~Rudnicki and A.~Rybnikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and L.~Sinha and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and P.~Sznajder and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and A.~Townsend and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and B.~Ventura and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and M.~Wilfert and K.~Zaremba and P.~Zavada and M.~Zavertyaev and M.~Zemko and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{C}ontribution of exclusive diffractive processes to the measured azimuthal asymmetries in {SIDIS}}, year = {2019}, eprint = {1912.10322}, note = {arXiv:1912.10322v1} }
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Hadron leptoproduction in Semi-Inclusive measurements of Deep-Inelastic Scattering (SIDIS) on unpolarised nucleons allows one to get information on the intrinsic transverse momentum of quarks in a nucleon and on the Boer-Mulders function through the measurement of azimuthal modulations in the cross section. These modulations were recently measured by the HERMES experiment at DESY on proton and deuteron targets, and by the COMPASS experiment using the CERN SPS muon beam and a $^6$LiD target. In both cases, the amplitudes of the $\cos\phi_h$ and $\cos 2\phi_h$ modulations show strong kinematic dependences for both positive and negative hadrons. It has been known since some time that the measured final-state hadrons in those SIDIS experiments receive a contribution from exclusive diffractive production of vector mesons, particularly important at large values of $z$, the fraction of the virtual photon energy carried by the hadron. In previous measurements of azimuthal asymmetries this contribution was not taken into account, because it was not known that it could distort the azimuthal modulations. Presently, a method to evaluate the contribution of the exclusive reactions to the azimuthal asymmetries measured by COMPASS has been developed. The subtraction of this contribution results in a better understanding of the kinematic effects, and the remaining non-zero $\cos 2\phi_h$ modulation gives indication for a non-zero Boer-Mulders effect.
The MPGD-Based Photon Detectors for the upgrade of COMPASS RICH-1
J. Agarwala, M. Alexeev, C.D.R. Azevedo, F. Bradamante, A. Bressan, M. Buchele, M. Chiosso, C. Chatterjee, P. Ciliberti, S. Dalla Torre, S. Dasgupta, O. Denisov, M. Finger, M. Finger Jr, H. Fischer, M. Gregori, G. Hamar, F. Herrmann, S. Levorato, A. Martin, et al (9)
Jul 25 2019 physics.ins-det hep-ex nucl-ex arXiv:1907.10482v1

@misc{1907.10482, author = {J.~Agarwala and M.~Alexeev and C.D.R.~Azevedo and F.~Bradamante and A.~Bressan and M.~Buchele and M.~Chiosso and C.~Chatterjee and P.~Ciliberti and S.~Dalla Torre and S.~Dasgupta and O.~Denisov and M.~Finger and M.~Finger Jr and H.~Fischer and M.~Gregori and G.~Hamar and F.~Herrmann and S.~Levorato and A.~Martin and G.~Menon and D.~Panzieri and G.~Sbrizzai and S.~Schopferer and M.~Slunecka and M.~Sulc and F.~Tessarotto and J.F.C.A.~Veloso and Y.~X.~Zhao}, title = {{T}he {MPGD}-{B}ased {P}hoton {D}etectors for the upgrade of {COMPASS} {RICH}-1}, year = {2019}, eprint = {1907.10482}, note = {arXiv:1907.10482v1} }
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After pioneering gaseous detectors of single photon for RICH applications using CsI solid state photocathodes in MWPCs within the RD26 collaboration and by the constructions for the RICH detector of the COMPASS experiment at CERN SPS, in 2016 we have upgraded COMPASS RICH by novel gaseous photon detectors based on MPGD technology. Four novel photon detectors, covering a total active area of 1.5~m$^2$, have been installed in order to cope with the challenging efficiency and stability requirements of the COMPASS physics programme. They are the first application in an experiment of MPGD-based single photon detectors. All aspects of the upgrade are presented, including engineering, mass production, quality assessment and performance. Perspectives for further developments in the field of gaseous single photon detectors are also indicated.
Radiogenic backgrounds in the NEXT double beta decay experiment
NEXT Collaboration, P. Novella, B. Palmeiro, M. Sorel, A. Usón, P. Ferrario, J.J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, I.J. Arnquist, C.D.R Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, N. Byrnes, S. Cárcel, J.V. Carrión, S. Cebrián, et al (71)
Jun 03 2019 physics.ins-det hep-ex arXiv:1905.13625v3

@misc{1905.13625, author = {NEXT Collaboration and P.~Novella and B.~Palmeiro and M.~Sorel and A.~Usón and P.~Ferrario and J.J.~Gómez-Cadenas and C.~Adams and V.~Álvarez and L.~Arazi and I.J.~Arnquist and C.D.R Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and G.~Díaz López and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and A.F.M.~Fernandes and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and S.~Ghosh and A.~Goldschmidt and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and P.~Herrero and V.~Herrero and Y.~Ifergan and S.~Johnston and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and G.~Martínez-Lema and A.D.~McDonald and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and D.R.~Nygren and A.~Para and J.~Pérez and F.~Psihas and M.~Querol and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and Y.~Rodríguez García and J.~Rodríguez and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and T.~Stiegler and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and R.~Webb and R.~Weiss-Babai and J.T.~White and K.~Woodruff and N.~Yahlali}, title = {{R}adiogenic backgrounds in the {NEXT} double beta decay experiment}, year = {2019}, eprint = {1905.13625}, note = {arXiv:1905.13625v3} }
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Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity-induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in $^{136}$Xe are analyzed to derive a total background rate of (0.84$\pm$0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT Collaboration. A spectral fit to this model yields the specific contributions of $^{60}$Co, $^{40}$K, $^{214}$Bi and $^{208}$Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25$\pm$0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5$\sigma$ after 1 year of data taking. The background measurement in a Q$_{\beta\beta}\pm$100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75$\pm$0.12) events.
Demonstration of the event identification capabilities of the NEXT-White detector
NEXT Collaboration, P. Ferrario, J.M. Benlloch-Rodríguez, G. Díaz López, J.A. Hernando Morata, M. Kekic, J. Renner, A. Usón, J.J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, I.J. Arnquist, C.D.R Azevedo, K. Bailey, F. Ballester, F.I.G.M. Borges, N. Byrnes, S. Cárcel, J.V. Carrión, et al (71)
May 31 2019 physics.ins-det hep-ex arXiv:1905.13141v3

@misc{1905.13141, author = {NEXT Collaboration and P.~Ferrario and J.M.~Benlloch-Rodríguez and G.~Díaz López and J.A.~Hernando Morata and M.~Kekic and J.~Renner and A.~Usón and J.J.~Gómez-Cadenas and C.~Adams and V.~Álvarez and L.~Arazi and I.J.~Arnquist and C.D.R Azevedo and K.~Bailey and F.~Ballester and F.I.G.M.~Borges and N.~Byrnes and S.~Cárcel and J.V.~Carrión and S.~Cebrián and E.~Church and C.A.N.~Conde and T.~Contreras and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and A.F.M.~Fernandes and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and S.~Ghosh and A.~Goldschmidt and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and J.~Haefner and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and P.~Herrero and V.~Herrero and Y.~Ifergan and S.~Johnston and B.J.P.~Jones and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and G.~Martínez-Lema and A.D.~McDonald and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and F.~Psihas and M.~Querol and J.~Repond and S.~Riordan and L.~Ripoll and Y.~Rodríguez García and J.~Rodríguez and L.~Rogers and B.~Romeo and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and R.~Webb and R.~Weiss-Babai and J.T.~White and K.~Woodruff and N.~Yahlali}, title = {{D}emonstration of the event identification capabilities of the {NEXT}-{W}hite detector}, year = {2019}, eprint = {1905.13141}, note = {arXiv:1905.13141v3} }
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In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a \TO calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of $71.6 \pm 1.5_{\textrm{ stat}} \pm 0.3_{\textrm{ sys}} \%$ for a background acceptance of $20.6 \pm 0.4_{\textrm{ stat}} \pm 0.3_{\textrm{ sys}} \%$ is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies.
Measurement of the cross section for hard exclusive $\pi^0$ leptoproduction
M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, P. Bordalo, F. Bradamante, et al (183)
Mar 29 2019 hep-ex arXiv:1903.12030v1

@misc{1903.12030, author = {M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and K.~Juraskova and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and P.-J.~Lin and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and C.~Naim and A.~Nagaytsev and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and H.~Schmieden and A.~Selyunin and L.~Silva and L.~Sinha and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and M.~Wilfert and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and Y.~Zhao and M.~Ziembicki}, title = {{M}easurement of the cross section for hard exclusive $\pi^0$ leptoproduction}, year = {2019}, eprint = {1903.12030}, note = {arXiv:1903.12030v1} }
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We report on a measurement of hard exclusive $\pi^0$ muoproduction on the proton by COMPASS using 160 GeV/$c$ polarised $\mu^+$ and $\mu^-$ beams of the CERN SPS impinging on a liquid hydrogen target. From the average of the measured $\mu^+$ and $\mu^-$ cross sections, the virtual-photon proton cross section is determined as a function of the squared four-momentum transfer between initial and final proton in the range $0.08\,(\text{GeV/}c)^2 < |t| < 0.64\,(\text{GeV/}c)^2$. The average kinematics of the measurement are $\langle Q^2 \rangle =2.0\; {(\text{GeV}/c)^2}$, $\langle \nu \rangle = 12.8\; {\text{GeV}}$, $\langle x_{Bj} \rangle = 0.093 $ and $\langle -t \rangle = 0.256\; {(\text{GeV}/c)^2} $. Fitting the azimuthal dependence reveals a combined contribution by transversely and longitudinally polarised photons of $(8.1 \ \pm \ 0.9_{\text{stat}}{}_{- \ 1.0}^{+ \ 1.1}\big\rvert_{\text{sys}})\,{\text{nb}}/{(\text{GeV}/c)^{2}}$, as well as transverse-transverse and longitudinal-transverse interference contributions of $(-6.0 \pm 1.3_{\text{stat}}{}_{- \ 0.7}^{+ \ 0.7}\big\rvert_{\text{sys}})\,{\text{nb}}/{(\text{GeV}/c)^{2}}$ and $(1.4 \pm 0.5_{\text{stat}}{}_{- \ 0.2}^{+ \ 0.3}\big\rvert_{\text{sys}})\,{\text{nb}}/{(\text{GeV}/c)^{2}}$, respectively. Our results provide important input for modelling Generalised Parton Distributions. In the context of the phenomenological Goloskokov-Kroll model, the statistically significant transverse-transverse interference contribution constitutes clear experimental evidence for the chiral-odd GPD $\overline{E}_T$.
The Hybrid MPGD-based photon detectors of COMPASS RICH-1
J.Agarwala, M.Alexeev, C.D.R.Azevedo, F.Bradamante, A.Bressan, M.Buechele, C.Chatterjee, M.Chiosso, A.Cicuttin, P.Ciliberti, M.L.Crespo, S.Dalla Torre, S.Dasgupta, O.Denisov, M.Finger, M.Finger Jr., H.Fischer, M.Gregori, G.Hamar, F.Herrmann, et al (11)
Dec 19 2018 physics.ins-det hep-ex nucl-ex arXiv:1812.06971v1

@misc{1812.06971, author = {J.Agarwala and M.Alexeev and C.D.R.Azevedo and F.Bradamante and A.Bressan and M.Buechele and C.Chatterjee and M.Chiosso and A.Cicuttin and P.Ciliberti and M.L.Crespo and S.Dalla Torre and S.Dasgupta and O.Denisov and M.Finger and M.Finger Jr.~and H.Fischer and M.Gregori and G.Hamar and F.Herrmann and S.Levorato and A.Martin and G.Menon and D.Panzieri and G.Sbrizzai and S.Schopferer and M.Slunecka and M.Sulc and F.Tessarotto and J.F.C.A.Veloso and Y.Zhao}, title = {{T}he {H}ybrid {MPGD}-based photon detectors of {COMPASS} {RICH}-1}, year = {2018}, eprint = {1812.06971}, howpublished = {Nucl. Instr. Methods A 2018}, note = {arXiv:1812.06971v1} }
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Novel gaseous detectors of single photons for RICH applications have been developed and installed on COMPASS RICH-1 in 2016. They have a hybrid architecture consisting of two staggered THGEM layers (one equipped with a CsI photoconverting layer) and a bulk Micromegas; they cover a total area of 1.4 squared meters and operate stably and efficiently. They provide a single photon angular resolution of ~ 1.8 mrad and about 10 detected photons per ring at saturation. The main aspects of their construction and commissioning, their characterization and performance figures are presented.
Measurement of $P_T$-weighted Sivers asymmetries in leptoproduction of hadrons
M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, V. Barone, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E. R. Bielert, et al (193)
Sep 11 2018 hep-ex arXiv:1809.02936v1

@misc{1809.02936, author = {M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and V.~Barone and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and C.~Elia and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and K.~Juraskova and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and A.A.~Lednev and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and H.~Schmieden and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and F.~Sozzi and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and M.~Wilfert and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki}, title = {{M}easurement of ${P}_{T}$-weighted {S}ivers asymmetries in leptoproduction of hadrons}, year = {2018}, eprint = {1809.02936}, note = {arXiv:1809.02936v1} }
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The transverse spin asymmetries measured in semi-inclusive leptoproduction of hadrons, when weighted with the hadron transverse momentum $P_T$, allow for the extraction of important transverse-momentum-dependent distribution functions. In particular, the weighted Sivers asymmetries provide direct information on the Sivers function, which is a leading-twist distribution that arises from a correlation between the transverse momentum of an unpolarised quark in a transversely polarised nucleon and the spin of the nucleon. Using the high-statistics data collected by the COMPASS Collaboration in 2010 with a transversely polarised proton target, we have evaluated two types of $P_T$-weighted Sivers asymmetries, which are both proportional to the product of the firsttransverse moment of the Sivers function and of the fragmentation function. The results are compared to the standard unweighted Sivers asymmetries and used to extract the first transverse moments of the Sivers distributions for $u$ and $d$ quarks.
Letter of Intent: A New QCD facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER)
B. Adams, C.A. Aidala, R.Akhunzyanov, G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, A. Azhibekov, B. Badelek, F. Balestra, M. Ball, J. Barth, R.Beck, Y. Bedfer, et al (247)
Aug 03 2018 hep-ex physics.ins-det arXiv:1808.00848v6

@misc{1808.00848, author = {B.~Adams and C.A.~Aidala and R.Akhunzyanov and G.D.~Alexeev and M.G.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and A.~Azhibekov and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.Beck and Y.~Bedfer and J.~Berenguer Antequera and J.C.~Bernauer and J.Bernhard and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buchele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and X.~Chen and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and P.~Correia and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and N.~Dashyan and I.~Denisenko and O.Yu.~Denisov and L.~Dhara and N.~d'Hose and F.~Donato and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Dunnweber and R.R.~Dusaev and M.~Dziewiecki and A.~Dzyuba and A.~Efremov and P.~Egelhof and A.~Elagin and P.D.~Eversheim and M.~Faessler and J.~Fedotova and A.~Ferrero and M.~Finger and M.~Finger Jr.~and H.~Fischer and C.~Franco and J.M.~Friedrich and V.~Frolov and A.~Futch and F.Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and S.~Gevorkyan and Y.~Ghandilyan and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and R.I.~Gushterski and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and X.~He and R.~Heitz and F.~Herrmann and N.~Horikawa and C.-Y.~Hsieh and S.~Huber and A.~Inglessi and A.~Ilyichev and T.~Isataev and S.~Ishimoto and A.~Ivanov and N.~Ivanov and Yu.~Ivanshin and T.~Iwata and M.~Jandek and V.~Jary and C.-M.~Jen and R.~Joosten and P.~Joerg and K.~Juraskova and E.~Kabuss and A.~Kabyshev and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and M.~Kim and O.~Kiselev and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and A.~Koval and Z.~Kral and M.~Kraemer and F.~Krinner and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and K.~Kuterbekov and I.I.~Kuznetsov and A.~Kveton and E.A.~Levchenko and S.~Levorato and Y.-S.~Lian and Y.~Liang and J.~Lichtenstadt and P.-J.~Lin and K.~Liu and M.X.~Liu and R.~Longo and W.~Lorenzon and M.~Losekamm and V.E.~Lyubovitskij and E.~Maev and A.~Maggiora and A.~Magnon and V.~Makarenko and N.~Makins and N.~Makke and G.K.~Mallot and A.~Maltsev and S.A.~Mamon and B.~Marianski and A.~Martin and H.~Marukyan and J.~Marzec and N.~Masi and J.~Matousek and H.~Matsuda and G.~Mattson and G.V.~Meshcheryakov and W.~Meyer and M.~Meyer and Yu.V.Mikhailov and M.~Mikhasenko and M.~Minot and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and C.Naim and D.~Neyret and G.~Nigmatkulov and A.~Mkrtchyan and H.~Mkrtchyan and J.~Novy and W.-D.~Nowak and F.~Nozzoli and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and J.D.~Osborn and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and D.V.~Peshekhonov and M.~Pesek and M.~Peskova and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and T.~Poeschl and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and R.~Raymond and G.~Reicherz and C.~Riedl and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and M.~Sarsour and I.A.~Savin and G.~Sbrizzai and H.~Schmieden and E.~Seder and A.~Selyunin and H.~Simon and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and P.~Sznajder and M.~Tasevsky and V.~Tchekhovski and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vassiliev and A.~Vauth and B.M.~Veit and B.~Ventura and J.~Veloso and A.~Vidon and M.~Virius and A.~Vorobyev and M.~Wagner and S.~Wallner and M.~Wilfert and Z.~Xiao and N.~Xu and J.~Yang and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and H.~Zhao and Y.~Zhao and N.~Zhuravlev and M.~Ziembicki and P.~Zuccon}, title = {{L}etter of {I}ntent: {A} {N}ew {QCD} facility at the {M}2 beam line of the {CERN} {SPS} ({COMPASS}++/{AMBER})}, year = {2018}, eprint = {1808.00848}, note = {arXiv:1808.00848v6} }
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A New QCD facility at the M2 beam line of the CERN SPS COMPASS++/AMBER
The MPGD-Based Photon Detectors for the upgrade of COMPASS RICH-1 and beyond
J. Agarwala, M. Alexeev, C.D.R. Azevedo, F. Bradamante, A. Bressan, M. Buchele, M. Chiosso, C. Chatterjee, P. Ciliberti, S. Dalla Torre, S. Dasgupta, O. Denisov, M. Finger, M. Finger Jr, H. Fischer, M. Gregori, G. Hamar, F. Herrmann, S. Levorato, A. Martin, et al (9)
Jul 04 2018 physics.ins-det hep-ex nucl-ex arXiv:1807.00816v1

@misc{1807.00816, author = {J.~Agarwala and M.~Alexeev and C.D.R.~Azevedo and F.~Bradamante and A.~Bressan and M.~Buchele and M.~Chiosso and C.~Chatterjee and P.~Ciliberti and S.~Dalla Torre and S.~Dasgupta and O.~Denisov and M.~Finger and M.~Finger Jr and H.~Fischer and M.~Gregori and G.~Hamar and F.~Herrmann and S.~Levorato and A.~Martin and G.~Menon and D.~Panzieri and G.~Sbrizzai and S.~Schopferer and M.~Slunecka and M.~Sulc and F.~Tessarotto and J.F.C.A.~Veloso and Y.~Zhao}, title = {{T}he {MPGD}-{B}ased {P}hoton {D}etectors for the upgrade of {COMPASS} {RICH}-1 and beyond}, year = {2018}, eprint = {1807.00816}, note = {arXiv:1807.00816v1} }
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After pioneering gaseous detectors of single photon for RICH applications using CsI solid state photocathodes in MWPCs within the RD26 collaboration and by the constructions for the RICH detector of the COMPASS experiment at CERN SPS, in 2016 we have upgraded COMPASS RICH by novel gaseous photon detectors based on MPGD technology. Four novel photon detectors, covering a total active area of 1.5~m$^2$, have been installed in order to cope with the challenging efficiency and stability requirements of the COMPASS physics programme. These detectors are the first application in an experiment of MPGD-based single photon detectors. All aspects of the upgrade are presented, including engineering, mass production, quality assessment and performance. Perspectives for further developments in the field of gaseous single photon detectors are also presented.
Electroluminescence TPCs at the thermal diffusion limit
C.A.O. Henriques, C.M.B. Monteiro, D. González-Díaz, C.D.R Azevedo, E.D.C. Freitas, R.D.P. Mano, M.R. Jorge, A.F.M. Fernandes, J.J. Gómez-Cadenas, L.M.P. Fernandes, C. Adams, V. Álvarez, L. Arazi, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, A. Botas, S. Cárcel, J.V. Carrión, et al (61)
Jun 18 2018 physics.ins-det hep-ex arXiv:1806.05891v2

@misc{1806.05891, author = {C.A.O.~Henriques and C.M.B.~Monteiro and D.~González-Díaz and C.D.R Azevedo and E.D.C.~Freitas and R.D.P.~Mano and M.R.~Jorge and A.F.M.~Fernandes and J.J.~Gómez-Cadenas and L.M.P.~Fernandes and C.~Adams and V.~Álvarez and L.~Arazi and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Botas and S.~Cárcel and J.V.~Carrión and S.~Cebrián and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and P.~Ferrario and A.L.~Ferreira and J.~Generowicz and A.~Goldschmidt and R.~Guenette and R.M.~Gutiérrez and K.~Hafidi and J.~Hauptman and A.I.~Hernandez and J.A.~Hernando Morata and V.~Herrero and S.~Johnston and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and J.~Martín-Albo and A.~Martínez and G.~Martínez-Lema and A.~McDonald and F.~Monrabal and F.J.~Mora and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and F.~Psihas and M.~Querol and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and J.~Rodríguez and L.~Rogers and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali}, title = {{E}lectroluminescence {TPC}s at the thermal diffusion limit}, year = {2018}, eprint = {1806.05891}, note = {arXiv:1806.05891v2} }
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The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the ${}^{136}$Xe isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO${}_{2}$, CH${}_{4}$ and CF${}_{4}$) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 mm/$\sqrt{\mathrm{m}}$ for pure xenon down to 2.5 mm/$\sqrt{\mathrm{m}}$ using additive concentrations of about 0.05%, 0.2% and 0.02% for CO${}_{2}$, CH${}_{4}$ and CF${}_{4}$, respectively. Our results show that CF${}_{4}$ admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH${}_{4}$ presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO${}_{2}$ and CH${}_{4}$ show potential as molecular additives in a large xenon TPC, CH${}_{4}$ showing the best performance and stability to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%.
The novel photon detectors based on MPGD technologies for the upgrade of COMPASS RICH-1
J.Agarwala, M.Alexeev, C.D.R.Azevedo, R.Birsa, F.Bradamante, A.Bressan, C.Chatterjee, M.Chiosso, A.Cicuttin, P.Ciliberti, M.L.Crespo, S.Dalla Torre, S.S.Dasgupta, O.Denisov, M.Finger, M.Finger Jr., B.Gobbo, M.Gregori, G.Hamar, S.Levorato, et al (15)
Apr 17 2018 physics.ins-det hep-ex nucl-ex arXiv:1804.05765v1

@misc{1804.05765, author = {J.Agarwala and M.Alexeev and C.D.R.Azevedo and R.Birsa and F.Bradamante and A.Bressan and C.Chatterjee and M.Chiosso and A.Cicuttin and P.Ciliberti and M.L.Crespo and S.Dalla Torre and S.S.Dasgupta and O.Denisov and M.Finger and M.Finger Jr.~and B.Gobbo and M.Gregori and G.Hamar and S.Levorato and A.Maggiora and A.Martin and G.Menon and J.Novy and D.Panzieri and F.A.B.Pereira and C.A.Santos and G.Sbrizzai and M.Slunecka and K.Steiger and L.Steiger and M.Sulc and F.Tessarotto and J.F.C.A.Veloso and Y.Zhao}, title = {{T}he novel photon detectors based on {MPGD} technologies for the upgrade of {COMPASS} {RICH}-1}, year = {2018}, eprint = {1804.05765}, note = {arXiv:1804.05765v1} }
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The RICH-1 Detector of the COMPASS experiment at CERN SPS has undergone an important upgrade in 2016. Four new photon detectors, based on MPGD technology and covering a total active area larger than 1.2~$m^2$ have replaced the previously used MWPC-based photon detectors. The new detector architecture, resulting from a dedicated, eight years long, R\&D program, consists in a hybrid MPGD combination of two THGEMs and a Micromegas stage; the first THGEM, coated with a CsI layer, acts as a reflective photocathode. The signals are extracted from the anode pads by capacitive coupling and read-out by analog front-end electronics based on the APV25 chip. The new COMPASS RICH-1 photon detectors are described in detail: the detector design, the engineering aspects, the mass production, and the quality assessment are discussed. The assembly of the MPGD components and the installation of the new detectors are illustrated together with the main aspects of the commissioning. Preliminary indication of performance results are also presented.
Electron drift properties in high pressure gaseous xenon
NEXT Collaboration, A. Simón, R. Felkai, G. Martínez-Lema, F. Monrabal, D. González-Díaz, M. Sorel, J.A. Hernando Morata, J.J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, C.D.R. Azevedo, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, A. Botas, S. Cárcel, J.V. Carrión, S. Cebrián, C.A.N. Conde, et al (56)
Apr 06 2018 physics.ins-det hep-ex nucl-ex arXiv:1804.01680v3

@misc{1804.01680, author = {NEXT Collaboration and A.~Simón and R.~Felkai and G.~Martínez-Lema and F.~Monrabal and D.~González-Díaz and M.~Sorel and J.A.~Hernando Morata and J.J.~Gómez-Cadenas and C.~Adams and V.~Álvarez and L.~Arazi and C.D.R.~Azevedo and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Botas and S.~Cárcel and J.V.~Carrión and S.~Cebrián and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and A.~Goldschmidt and R.~Guenette and R.M.~Gutiérrez and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and V.~Herrero and S.~Johnston and B.J.P.~Jones and M.Kekic and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and J.~Martín-Albo and A.~Martínez and A.D.~McDonald and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and J.~Rodríguez and L.~Rogers and C.~Romo and F.P.~Santos and J.M.F.~dos Santos and C.~Sofka and T.~Stiegler and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali}, title = {{E}lectron drift properties in high pressure gaseous xenon}, year = {2018}, eprint = {1804.01680}, note = {arXiv:1804.01680v3} }
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Gaseous time projection chambers (TPC) are a very attractive detector technology for particle tracking. Characterization of both drift velocity and diffusion is of great importance to correctly assess their tracking capabilities. NEXT-White is a High Pressure Xenon gas TPC with electroluminescent amplification, a 1:2 scale model of the future NEXT-100 detector, which will be dedicated to neutrinoless double beta decay searches. NEXT-White has been operating at Canfranc Underground Laboratory (LSC) since December 2016. The drift parameters have been measured using $^{83m}$Kr for a range of reduced drift fields at two different pressure regimes, namely 7.2 bar and 9.1 bar. The results have been compared with Magboltz simulations. Agreement at the 5% level or better has been found for drift velocity, longitudinal diffusion and transverse diffusion.
Calibration of the NEXT-White detector using $^{83m}\mathrm{Kr}$ decays
G. Martínez-Lema, J.A. Hernando Morata, B. Palmeiro, A. Botas, P. Ferrario, F. Monrabal, A. Laing, J. Renner, A. Simón, J.J. Gómez-Cadenas, C. Adams, V. Álvarez, L. Arazi, C.D.R. Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, S. Cárcel, J.V. Carrión, et al (57)
Apr 06 2018 physics.ins-det hep-ex arXiv:1804.01780v5

@misc{1804.01780, author = {G.~Martínez-Lema and J.A.~Hernando Morata and B.~Palmeiro and A.~Botas and P.~Ferrario and F.~Monrabal and A.~Laing and J.~Renner and A.~Simón and J.J.~Gómez-Cadenas and C.~Adams and V.~Álvarez and L.~Arazi and C.D.R.~Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and S.~Cárcel and J.V.~Carrión and S.~Cebrián and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and A.~Goldschmidt and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and V.~Herrero and S.~Johnston and B.J.P.~Jones and M.Kekic and L.~Labarga and P.~Lebrun and N.~López-March and M.~Losada and J.~Martín-Albo and A.~Martínez and A.D.~McDonald and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and D.R.~Nygren and A.~Para and J.~Pérez and M.~Querol and J.~Repond and S.~Riordan and L.~Ripoll and J.~Rodríguez and L.~Rogers and C.~Romo and F.P.~Santos and J.M.F.~dos Santos and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlalib}, title = {{C}alibration of the {NEXT}-{W}hite detector using $^{83m}\mathrm{{K}r}$ decays}, year = {2018}, eprint = {1804.01780}, note = {arXiv:1804.01780v5} }
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The NEXT-White (NEW) detector is currently the largest radio-pure high-pressure xenon gas time projection chamber with electroluminescent readout in the world. NEXT-White has been operating at Laboratorio Subterráneo de Canfranc (LSC) since October 2016. This paper describes the calibrations performed with $^{83m}\mathrm{Kr}$ decays during a long run taken from March to November 2017 (Run II). Krypton calibrations are used to correct for the finite drift-electron lifetime as well as for the dependence of the measured energy on the event position which is mainly caused by variations in solid angle coverage. After producing calibration maps to correct for both effects we measure an excellent energy resolution for 41.5 keV point-like deposits of (4.553 $\pm$ 0.010 (stat.) $\pm$ 0.324 (sys.)) % FWHM in the full chamber and (3.804 $\pm$ 0.013 (stat.) $\pm$ 0.112 (sys.)) % FWHM in a restricted fiducial volume. Using naive 1/$\sqrt{E}$ scaling, these values translate into resolutions of (0.516 $\pm$ 0.0014 (stat.) $\pm$ 0.0421 (sys.)) % FWHM and (0.4943 $\pm$ 0.0017 (stat.) $\pm$ 0.0146 (sys.)) % FWHM at the $Q_{\beta\beta}$ energy of xenon double beta decay (2458 keV), well within range of our target value of 1%.
Measurement of radon-induced backgrounds in the NEXT double beta decay experiment
NEXT Collaboration, P. Novella, B. Palmeiro, A. Simón, M. Sorel, C. Adams, P. Ferrario, G. Martínez-Lema, F. Monrabal, G. Zuzel, J.J. Gómez-Cadenas, V. Álvarez, L. Arazi, C.D.R Azevedo, K. Bailey, F. Ballester, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, A. Botas, S. Cárcel, et al (62)
Apr 03 2018 physics.ins-det hep-ex nucl-ex arXiv:1804.00471v3

@misc{1804.00471, author = {NEXT Collaboration and P.~Novella and B.~Palmeiro and A.~Simón and M.~Sorel and C.~Adams and P.~Ferrario and G.~Martínez-Lema and F.~Monrabal and G.~Zuzel and J.J.~Gómez-Cadenas and V.~Álvarez and L.~Arazi and C.D.R Azevedo and K.~Bailey and F.~Ballester and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Botas and S.~Cárcel and J.V.~Carrión and S.~Cebrián and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and A.F.M.~Fernandes and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and J.~Generowicz and A.~Goldschmidt and D.~González-Díaz and R.~Guenette and R.M.~Gutiérrez and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and J.A.~Hernando Morata and V.~Herrero and S.~Johnston and B.J.P.~Jones and M.~Kekic and L.~Labarga and A.~Laing and P.~Lebrun and N.~López-March and M.~Losada and R.D.P.~Mano and J.~Martín-Albo and A.~Martínez and A.~McDonald and C.M.B.~Monteiro and F.J.~Mora and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and D.R.~Nygren and A.~Para and J.~Pérez and F.~Psihas and M.~Querol and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and J.~Rodríguez and L.~Rogers and C.~Romo-Luque and F.P.~Santos and J.M.F.~dos Santos and C.~Sofka and T.~Stiegler and J.F.~Toledo and J.~Torrent and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali}, title = {{M}easurement of radon-induced backgrounds in the {NEXT} double beta decay experiment}, year = {2018}, eprint = {1804.00471}, note = {arXiv:1804.00471v3} }
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The measurement of the internal $^{222}$Rn activity in the NEXT-White detector during the so-called Run-II period with $^{136}$Xe-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity is measured through the alpha production rate induced in the fiducial volume by $^{222}$Rn and its alpha-emitting progeny. The specific activity is measured to be $(38.1\pm 2.2~\mathrm{(stat.)}\pm 5.9~\mathrm{(syst.)})$~mBq/m$^3$. Radon-induced electrons have also been characterized from the decay of the $^{214}$Bi daughter ions plating out on the cathode of the time projection chamber. From our studies, we conclude that radon-induced backgrounds are sufficiently low to enable a successful NEXT-100 physics program, as the projected rate contribution should not exceed 0.1~counts/yr in the neutrinoless double beta decay sample.
Light isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 GeV/${\it c}$
M. Aghasyan, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, et al (205)
Feb 19 2018 hep-ex hep-ph arXiv:1802.05913v2

@misc{1802.05913, author = {M.~Aghasyan and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Hass and D.~Hahne and G.~Hamar and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and K.~Juraskova and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and I.I.~Kuznetsov and A.~Kveton and A.A.~Lednev and E.A.~Levchenko and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.~S.~Rogacheva and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and T.~Schluter and S.~Schmeing and H.~Schmieden and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and A.Vidon and M.~Virius and S.~Wallner and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki}, title = {{L}ight isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 {G}e{V}/${\it c}$}, year = {2018}, eprint = {1802.05913}, note = {arXiv:1802.05913v2} }
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We have performed the most comprehensive resonance-model fit of $\pi^-\pi^-\pi^+$ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction $\pi^- + p \to \pi^-\pi^-\pi^+ + p_\text{recoil}$ with a 190 GeV/$c$ pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, $0.5 < m_{3\pi} < 2.5$ GeV/$c^2$, and simultaneously in 11 bins of the reduced four-momentum transfer squared, $0.1 < t' < 1.0$ $($GeV$/c)^2$, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{++}$, $2^{-+}$, $4^{++}$, and spin-exotic $1^{-+}$ quantum numbers. The model contains the well-known resonances $\pi(1800)$, $a_1(1260)$, $a_2(1320)$, $\pi_2(1670)$, $\pi_2(1880)$, and $a_4(2040)$. In addition, it includes the disputed $\pi_1(1600)$, the excited states $a_1(1640)$, $a_2(1700)$, and $\pi_2(2005)$, as well as the resonancelike $a_1(1420)$. We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 $t'$ bins. We extract the relative branching fractions of the $\rho(770) \pi$ and $f_2(1270) \pi$ decays of $a_2(1320)$ and $a_4(2040)$, where the former one is measured for the first time. In a novel approach, we extract the $t'$ dependence of the intensity of the resonances and of their phases. The $t'$ dependence of the intensities of most resonances differs distinctly from the $t'$ dependence of the nonresonant components. For the first time, we determine the $t'$ dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances.
Transverse Extension of Partons in the Proton probed by Deeply Virtual Compton Scattering
R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, et al (207)
Feb 09 2018 hep-ex nucl-ex arXiv:1802.02739v2

@misc{1802.02739, author = {R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and E.~Burtin and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and K.~Juraskova and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and I.I.~Kuznetsov and A.~Kveton and A.A.~Lednev and E.A.~Levchenko and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and G.~Pesaro and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.~S.~Rogacheva and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and H.~Schmieden and K.~Schoennig and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.~M.~Veit and J.~Veloso and A.Vidon and M.~Virius and S.~Wallner and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki}, title = {{T}ransverse {E}xtension of {P}artons in the {P}roton probed by {D}eeply {V}irtual {C}ompton {S}cattering}, year = {2018}, eprint = {1802.02739}, doi = {10.1016/j.physletb.2019.04.038}, note = {arXiv:1802.02739v2} }
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We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/$c$ polarized $\mu^+$ and $\mu^-$ beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured $\mu^+$ and $\mu^-$ cross sections for deeply virtual Compton scattering on the squared four-momentum transfer $t$ from the initial to the final final proton. The slope $B$ of the $t$-dependence is fitted with a single exponential function, which yields $B=(4.3 \ \pm \ 0.6_{\text{stat}}\_{- \ 0.3}^{+ \ 0.1}\big\rvert_{\text{sys}}) (\text{GeV}/c)^{-2}$. This result can be converted into an average transverse extension of partons in the proton, $\sqrt{\langle r_{\perp}^2 \rangle} = (0.58 \ \pm \ 0.04_{\text{stat}}\_{- \ 0.02}^{+ \ 0.01}\big\rvert_{\text{sys}})\text{fm}$. For this measurement, the average virtuality of the photon mediating the interaction is $\langle Q^2 \rangle = 1.8\,(\text{GeV/}c)^2$ and the average value of the Bjorken variable is $\langle x_{\text{Bj}} \rangle = 0.056$.
K$^{-}$ over K$^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy
R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E. R. Bielert, et al (191)
Feb 05 2018 hep-ex hep-ph arXiv:1802.00584v2

@misc{1802.00584, author = {R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and C.~Elia and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and T.~Iwata and M.~Jandek and T.~Jary and R.~Joosten and P.~Joerg and K.~Juraskova and E.~Kabuss and F.~Kaspar and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and A.A.~Lednev and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevskiy and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and H.~Schmieden and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and B.M.~Veit and J.~Veloso and A.Vidon and M.~Virius and M.~Wagner and S.~Wallner and M.~Wilfert and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki}, title = {{K}$^{-}$ over {K}$^{+}$ multiplicity ratio for kaons produced in {DIS} with a large fraction of the virtual-photon energy}, year = {2018}, eprint = {1802.00584}, note = {arXiv:1802.00584v2} }
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The K$^{-}$ over K$^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2>1$ (GeV/$c)^2$ for the photon virtuality and $W>5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/$c$ to 40 GeV/$c$, thereby restricting the range in Bjorken-$x$ to $0.01<x<0.40$. The $z$-dependence of the multiplicity ratio is studied for $z>0.75$. For very large values of $z$, $i.e.$ $z>0.8$, we observe the kaon multiplicity ratio to fall below the lower limits expected from calculations based on leading and next-to-leading order perturbative quantum chromodynamics. Also, the kaon multiplicity ratio shows a strong dependence on the missing mass of the single-kaon production process. This suggests that within the perturbative quantum chromodynamics formalism an additional correction may be required, which takes into account the phase space available for hadronisation.
Measurements of charging-up processes in THGEM-based particle detectors
M. Pitt, P. M. M. Correia, S. Bressler, A. E. C. Coimbra, D. Shaked Renous, C. D. R. Azevedo, J. F. C. A. Veloso, A. Breskin
Jan 03 2018 physics.ins-det hep-ex arXiv:1801.00533v2

@misc{1801.00533, author = {M.~Pitt and P.~M.~M.~Correia and S.~Bressler and A.~E.~C.~Coimbra and D.~Shaked Renous and C.~D.~R.~Azevedo and J.~F.~C.~A.~Veloso and A.~Breskin}, title = {{M}easurements of charging-up processes in {THGEM}-based particle detectors}, year = {2018}, eprint = {1801.00533}, note = {arXiv:1801.00533v2} }
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The time-dependent gain variation of detectors incorporating Thick Gas Electron Multipliers (THGEM) electrodes was studied in the context of charging-up processes of the electrode's insulating surfaces. An experimental study was performed to examine model-simulation results of the aforementioned phenomena, under various experimental conditions. The results indicate that in a stable detector's environment, the gain stabilization process is mainly affected by the charging-up of the detector's insulating surfaces caused by the avalanche charges. The charging-up is a transient effect, occurring during the detector's initial operation period; it does not affect its long-term operation. The experimental results are consistent with the outcome of model-simulations.
Demonstration of Single Barium Ion Sensitivity for Neutrinoless Double Beta Decay using Single Molecule Fluorescence Imaging
A.D.McDonald, B.J.P. Jones, D.R.Nygren, C. Adams, V.Alvarez, C.D.R. Azevedo, J.M. Benlloch-Rodrıguez, F.I.G.M. Borges, A. Botas, S. Carcel, J.V. Carrion, S. Cebrian, C.A.N. Conde, J. Dıaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, L.M.P. Fernandes, P. Ferrario, et al (54)
Nov 16 2017 physics.ins-det hep-ex nucl-ex arXiv:1711.04782v3

@misc{1711.04782, author = {A.D.McDonald and B.J.P.~Jones and D.R.Nygren and C.~Adams and V.Alvarez and C.D.R.~Azevedo and J.M.~Benlloch-Rodrıguez and F.I.G.M.~Borges and A.~Botas and S.~Carcel and J.V.~Carrion and S.~Cebrian and C.A.N.~Conde and J.~Dıaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and A.~Goldschmidt and J.J.~Gomez-Cadenas and D.~Gonzalez-Dıaz and R.M.~Gutierrez and R.~Guenette and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and J.A.~Hernando Morata and V.~Herrero and S.~Johnston and L.~Labarga and A.~Laing and P.~Lebrun and I.~Liubarsky and N.~Lopez-March and M.~Losada and J.~Martın-Albo and G.~Martınez-Lema and A.~Martınez and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and J.~Munoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and B.~Palmeiro and A.~Para and J.~Perez and M.~Querol and J.~Repond and J.~Renner and S.~Riordan and L.~Ripoll and J.~Rodrıguez and L.~Rogers and F.P.~Santos and J.M.F.~dos Santos and A.~Simon and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali}, title = {{D}emonstration of {S}ingle {B}arium {I}on {S}ensitivity for {N}eutrinoless {D}ouble {B}eta {D}ecay using {S}ingle {M}olecule {F}luorescence {I}maging}, year = {2017}, eprint = {1711.04782}, note = {arXiv:1711.04782v3} }
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A new method to tag the barium daughter in the double beta decay of $^{136}$Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba$^{++}$) resolution at a transparent scanning surface has been demonstrated. A single-step photo-bleach confirms the single ion interpretation. Individual ions are localized with super-resolution ($\sim$2~nm), and detected with a statistical significance of 12.9~$\sigma$ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.
Status of COMPASS RICH-1 Upgrade with MPGD-based Photon Detectors
M. Alexeev, R Birsa, F. Bradamante, A. Bressan, M. Chiosso, P. Ciliberti, S. Dalla Torre, S. Dasgupta, O. Denisov, M. Finger, M. Finger Jr, H. Fishcher, B. Gobbo, M. Gregori, G. Hamar, F. Herrmann, K. Koenigsmann, S. Levorato, A. Maggiora, N. Makke, et al (15)
Oct 26 2017 physics.ins-det hep-ex nucl-ex arXiv:1710.09274v1

@misc{1710.09274, author = {M.~Alexeev and R Birsa and F.~Bradamante and A.~Bressan and M.~Chiosso and P.~Ciliberti and S.~Dalla Torre and S.~Dasgupta and O.~Denisov and M.~Finger and M.~Finger Jr and H.~Fishcher and B.~Gobbo and M.~Gregori and G.~Hamar and F.~Herrmann and K.~Koenigsmann and S.~Levorato and A.~Maggiora and N.~Makke and A.~Martin and G.~Menon and J.~Novy and D.~Panzieri and F.~A.~Pereira and C.~A.~Santos and G.~Sbrizzai and P.~Schiavon and S.~Schopferer and M.~Slunechka and K.~Steiger and L.~Steiger and M.~Sulc and F.~Tessarotto and J.~F.~C.~A.~Veloso}, title = {{S}tatus of {COMPASS} {RICH}-1 {U}pgrade with {MPGD}-based {P}hoton {D}etectors}, year = {2017}, eprint = {1710.09274}, note = {arXiv:1710.09274v1} }
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A Set of new MPGD-based Photon Detectors is being built for the upgrade of COMPASS RICH-1. The detectors cover a total active area of 1.4 m$^2$ and are based on a hybrid architecture consisting of two THGEM layers and a Micromegas. A CsI film on one THGEM acts as a reflective photocathode. The characteristics of the detector, the production of the components and their validation tests are described in detail.
Novel MPGD based Detectors of Single Photons in COMPASS RICH-1
J.Agarwala M.Alexeev, C.D.R.Azevedo, R.Birsa, F.Bradamante, A.Bressan, M.Buchele, C.Chatterjee, M.Chiosso, P.Ciliberti, S.Dalla Torre, S.Dasgupta, O.Denisov, M.Finger, M.Finger Jr., H.Fischer, B.Gobbo, M.Gregori, G.Hamar, F.Herrmann, S.Levorato, et al (17)
Oct 25 2017 physics.ins-det hep-ex arXiv:1710.08656v1

@misc{1710.08656, author = {J.Agarwala M.Alexeev and C.D.R.Azevedo and R.Birsa and F.Bradamante and A.Bressan and M.Buchele and C.Chatterjee and M.Chiosso and P.Ciliberti and S.Dalla Torre and S.Dasgupta and O.Denisov and M.Finger and M.Finger Jr.~and H.Fischer and B.Gobbo and M.Gregori and G.Hamar and F.Herrmann and S.Levorato and A.Maggiora and N.Makke and A.Martin and G.Menon and J.Novy and D.Panzieri and F.A.B.Pereira and C.A.Santos and G.Sbrizzai and S.Schopferer and M.Slunecka and K.Steiger and L.Steiger and M.Sulc and F.Tessarotto and J.F.C.A.Veloso and Y.X.Zhao}, title = {{N}ovel {MPGD} based {D}etectors of {S}ingle {P}hotons in {COMPASS} {RICH}-1}, year = {2017}, eprint = {1710.08656}, note = {arXiv:1710.08656v1} }
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COMPASS is a fixed target experiment at CERN SPS aimed to study Hadron Structure and Spectroscopy. Hadron Identification in the momentum range between 3 and 55 GeV/c is provided by a large gaseous Ring Imaging Cherenkov Counter (RICH-1). To cope with the challenges imposed by the new physics program of COMPASS, RICH-1 have been upgraded by replacing four MWPCs based photon detectors with newly developed MPGD based photon detectors. The architecture of the novel detectors is a hybrid combination of two layers of THGEMs and a MicroMegas. The top of the first THGEM is coated with CsI acting as a reflective photo-cathode. The anode is segmented in pads capacitively coupled to the APV-25 based readout. The new hybrid detectors have been commissioned during 2016 COMPASS data taking and stably operated during 2017 run. In this paper all aspects of the novel photon detectors for COMPASS RICH-1 are discussed.
Helium-Xenon mixtures to improve topological signature in high pressure gas Xenon TPCs
R. Felkai, F. Monrabal, D. Gonzalez-Díaz, M. Sorel, N. López-March, J.J. Gómez-Cadenas, C. Adams, V.Álvarez, L.Arazi, C.D.R.Azevedo, J.M.Benlloch-Rodríguez, F.I.G.M.Borges, A.Botas, S.Cárcel, J.V. Carrión, S. Cebrián, C.A.N. Conde, J. Díaz, M. Diesburg, J. Escada, et al (55)
Oct 17 2017 physics.ins-det hep-ex nucl-ex arXiv:1710.05600v4

@misc{1710.05600, author = {R.~Felkai and F.~Monrabal and D.~Gonzalez-Díaz and M.~Sorel and N.~López-March and J.J.~Gómez-Cadenas and C.~Adams and V.Álvarez and L.Arazi and C.D.R.Azevedo and J.M.Benlloch-Rodríguez and F.I.G.M.Borges and A.Botas and S.Cárcel and J.V.~Carrión and S.~Cebrián and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and A.~Goldschmidt and R.~Guenette and R.M.~Gutiérrez and K.~Hafidi and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and J.A.~Hernando Morata and V.~Herrero and S.~Johnston and B.J.P.~Jones and L.~Labarga and A.~Laing and P.~Lebrun and M.~Losada and J.~Martín-Albo and G.~Martínez-Lema and A.~Martínez and A.D.~McDonald and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and J.~Renner and J.~Repond and S.~Riordan and L.~Ripoll and C.~Romo and J.~Rodríguez and L.~Rogers and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and T.~Stiegler and J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali}, title = {{H}elium-{X}enon mixtures to improve topological signature in high pressure gas {X}enon {TPC}s}, year = {2017}, eprint = {1710.05600}, doi = {10.1016/j.nima.2018.07.013}, note = {arXiv:1710.05600v4} }
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Within the framework of xenon-based double beta decay experiments, we propose the possibility to improve the background rejection of an electroluminescent Time Projection Chamber (EL TPC) by reducing the diffusion of the drifting electrons while keeping nearly intact the energy resolution of a pure xenon EL TPC. Based on state-of-the-art microscopic simulations, a substantial addition of helium, around 10 or 15~\%, may reduce drastically the transverse diffusion down to 2.5~mm/$\sqrt{\mathrm{m}}$ from the 10.5~mm/$\sqrt{\mathrm{m}}$ of pure xenon. The longitudinal diffusion remains around 4~mm/$\sqrt{\mathrm{m}}$. Light production studies have been performed as well. They show that the relative variation in energy resolution introduced by such a change does not exceed a few percent, which leaves the energy resolution practically unchanged. The technical caveats of using photomultipliers close to an helium atmosphere are also discussed in detail.
Longitudinal double-spin asymmetry $A_1^{\rm p}$ and spin-dependent structure function $g_1^{\rm p}$ of the proton at small values of $x$ and $Q^2$
M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (209)
Oct 04 2017 hep-ex arXiv:1710.01014v1

@misc{1710.01014, author = {M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and I.I.~Kuznetsov and A.~Kveton and A.A.~Lednev and E.A.~Levchenko and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rogacheva and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and J.~Veloso and A.Vidon and M.~Virius and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki}, title = {{L}ongitudinal double-spin asymmetry ${A}_1^{\rm p}$ and spin-dependent structure function $g_1^{\rm p}$ of the proton at small values of $x$ and ${Q}^2$}, year = {2017}, eprint = {1710.01014}, note = {arXiv:1710.01014v1} }
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We present a precise measurement of the proton longitudinal double-spin asymmetry $A_1^{\rm p}$ and the proton spin-dependent structure function $g_1^{\rm p}$ at photon virtualities $0.006~({\rm GeV}/c)^2<Q^2 < 1~({\rm GeV}/c)^2$ in the Bjorken $x$ range of $4 \times 10^{-5} < x < 4 \times 10^{-2}$. The results are based on data collected by the COMPASS Collaboration at CERN using muon beam energies of $160~{\rm GeV}$ and $200~{\rm GeV}$. The statistical precision is more than tenfold better than that of the previous measurement in this region. In the whole range of $x$, the measured values of $A_1^{\rm p}$ and $g_1^{\rm p}$ are found to be positive. It is for the first time that spin effects are found at such low values of $x$.
Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering
M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (211)
Sep 22 2017 hep-ex nucl-ex arXiv:1709.07374v1

@misc{1709.07374, author = {M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and L.~Capozza and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and I.I.~Kuznetsov and A.~Kveton and A.A.~Lednev and E.A.~Levchenko and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Moretti and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rogacheva and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and J.~Veloso and A.Vidon and M.~Virius and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki}, title = {{T}ransverse-momentum-dependent {M}ultiplicities of {C}harged {H}adrons in {M}uon-{D}euteron {D}eep {I}nelastic {S}cattering}, year = {2017}, eprint = {1709.07374}, note = {arXiv:1709.07374v1} }
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A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality $Q^{2}>1$ (GeV/$c$)$^2$, invariant mass of the hadronic system $W > 5$ GeV/$c^2$, Bjorken scaling variable in the range $0.003 < x < 0.4$, fraction of the virtual photon energy carried by the hadron in the range $0.2 < z < 0.8$, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/$c)^2 < P_{\rm{hT}}^{2} < 3$ (GeV/$c$)$^2$. The multiplicities are presented as a function of $P_{\rm{hT}}^{2}$ in three-dimensional bins of $x$, $Q^2$, $z$ and compared to previous semi-inclusive measurements. We explore the small-$P_{\rm{hT}}^{2}$ region, i.e. $P_{\rm{hT}}^{2} < 1$ (GeV/$c$)$^2$, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger $P_{\rm{hT}}^{2}$, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small $P_{\rm{hT}}^{2}$ to study the dependence of the average transverse momentum $\langle P_{\rm{hT}}^{2}\rangle$ on $x$, $Q^2$ and $z$. The power-law behaviour of the multiplicities at large $P_{\rm{hT}}^{2}$ is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.
New analysis of $\eta\pi$ tensor resonances measured at the COMPASS experiment
A. Jackura, C. Fernandez-Ramirez, M. Mikhasenko, A. Pilloni, V. Mathieu, J. Nys, V. Pauk, A. P. Szczepaniak, G. Fox, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, et al (217)
Jul 11 2017 hep-ph hep-ex arXiv:1707.02848v1

@misc{1707.02848, author = {A.~Jackura and C.~Fernandez-Ramirez and M.~Mikhasenko and A.~Pilloni and V.~Mathieu and J.~Nys and V.~Pauk and A.~P.~Szczepaniak and G.~Fox and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and I.I.~Kuznetsov and A.~Kveton and A.A.~Lednev and E.A.~Levchenko and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rogacheva and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and T.~Schluter and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and J.~Veloso and A.Vidon and M.~Virius and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki}, title = {{N}ew analysis of $\eta\pi$ tensor resonances measured at the {COMPASS} experiment}, year = {2017}, eprint = {1707.02848}, note = {arXiv:1707.02848v1} }
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We present a new amplitude analysis of the $\eta\pi$ $D$-wave in $\pi^- p\to \eta\pi^- p$ measured by COMPASS. Employing an analytical model based on the principles of the relativistic $S$-matrix, we find two resonances that can be identified with the $a_2(1320)$ and the excited $a_2^\prime(1700)$, and perform a comprehensive analysis of their pole positions. For the mass and width of the $a_2$ we find $M=(1307 \pm 1 \pm 6)$~MeV and $\Gamma=(112 \pm 1 \pm 8)$~MeV, and for the excited state $a_2^\prime$ we obtain $M=(1720 \pm 10 \pm 60)$~MeV and $\Gamma=(280\pm 10 \pm 70)$~MeV, respectively.
Search for muoproduction of $X(3872)$ at COMPASS and indication of a new state $\widetilde{X}(3872)$
M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (208)
Jul 07 2017 hep-ex arXiv:1707.01796v2

@misc{1707.01796, author = {M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and A.~Bressan and M.~Buechele and V.E.~Burtsev and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and A.G.~Chumakov and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and R.R.~Dusaev and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and A.~Grasso and A.~Gridin and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and I.I.~Kuznetsov and A.~Kveton and A.A.~Lednev and E.A.~Levchenko and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and V.E.~Lyubovitskij and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and S.A.~Mamon and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and M.~Peskova and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rogacheva and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and B.I.~Vasilishin and A.~Vauth and J.~Veloso and A.Vidon and M.~Virius and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki}, title = {{S}earch for muoproduction of ${X}(3872)$ at {COMPASS} and indication of a new state $\widetilde{{X}}(3872)$}, year = {2017}, eprint = {1707.01796}, doi = {10.1016/j.physletb.2018.07.008}, note = {arXiv:1707.01796v2} }
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We have searched for exclusive production of exotic charmonia in the reaction $\mu^+~N \rightarrow \mu^+ (J\!/\!\psi\pi^+\pi^-)\pi^{\pm}~N'$ using COMPASS data collected with incoming muons of 160 GeV/$c$ and 200 GeV/$c$ momentum. In the $J\!/\!\psi\pi^+\pi^-$ mass distribution we observe a signal with a statistical significance of 4.1 $\sigma$. Its mass and width are consistent with those of the $X(3872)$. The shape of the $\pi^+\pi^-$ mass distribution from the observed decay into $J\!/\!\psi\pi^+\pi^-$ shows disagreement with previous observations for $X(3872)$. The observed signal may be interpreted as a possible evidence of a new charmonium state. It could be associated with a neutral partner of $X(3872)$ with $C = -1$ predicted by a tetraquark model. The product of cross section and branching fraction of the decay of the observed state into $J\!/\!\psi\pi^+\pi^-$ is determined to be 71$\pm$28(stat)$\pm$39(syst) pb.
Radiopurity assessment of the energy readout for the NEXT double beta decay experiment
S. Cebrián, J. Pérez, I. Bandac, L. Labarga, V. Álvarez, C.D.R. Azevedo, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, A. Botas, S. Cárcel, J.V. Carrión, C.A.N. Conde, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, L.M.P. Fernandes, P. Ferrario, A.L. Ferreira, et al (50)
Jun 20 2017 physics.ins-det hep-ex nucl-ex arXiv:1706.06012v2

@misc{1706.06012, author = {S.~Cebrián and J.~Pérez and I.~Bandac and L.~Labarga and V.~Álvarez and C.D.R.~Azevedo and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Botas and S.~Cárcel and J.V.~Carrión and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and A.~Goldschmidt and J.J.~Gómez-Cadenas and D.~González-Díaz and R.M.~Gutiérrez and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and J.A.~Hernando Morata and V.~Herrero and B.J.P.~Jones and A.~Laing and P.~Lebrun and I.~Liubarsky and N.~López-March and M.~Losada and J.~Martín-Albo and G.~Martínez-Lema and A.~Martínez and A.D.~McDonald and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and M.~Querol and J.~Renner and L.~Ripoll and o J.~Rodríguez and L.~Rogers and F.P.~Santos and J.M.F.~dos Santos and A.~Simón and C.~Sofka and M.~Sorel and T.~Stiegler and p J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and J.A.~Villar and R.~Webb and J.T.~White and N.~Yahlali}, title = {{R}adiopurity assessment of the energy readout for the {NEXT} double beta decay experiment}, year = {2017}, eprint = {1706.06012}, howpublished = {2017 JINST 12 T08003}, note = {arXiv:1706.06012v2} }
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The Neutrino Experiment with a Xenon Time-Projection Chamber (NEXT) experiment intends to investigate the neutrinoless double beta decay of 136Xe, and therefore requires a severe suppression of potential backgrounds. An extensive material screening and selection process was undertaken to quantify the radioactivity of the materials used in the experiment. Separate energy and tracking readout planes using different sensors allow us to combine the measurement of the topological signature of the event for background discrimination with the energy resolution optimization. The design of radiopure readout planes, in direct contact with the gas detector medium, was especially challenging since the required components typically have activities too large for experiments demanding ultra-low background conditions. After studying the tracking plane, here the radiopurity control of the energy plane is presented, mainly based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterráneo de Canfranc (Spain). All the available units of the selected model of photomultiplier have been screened together with most of the components for the bases, enclosures and windows. According to these results for the activity of the relevant radioisotopes, the selected components of the energy plane would give a contribution to the overall background level in the region of interest of at most 2.4 x 10-4 counts keV-1 kg-1 y-1, satisfying the sensitivity requirements of the NEXT experiment.
Application and performance of an ML-EM algorithm in NEXT
NEXT Collaboration, A. Simón, C. Lerche, F. Monrabal, J.J. Gómez-Cadenas, V. Álvarez, C.D.R. Azevedo, J.M. Benlloch-Rodríguez, F.I.G.M. Borges, A. Botas, S. Cárcel, J.V. Carrión, S. Cebrián, C.A.N. Conde, J. Díaz, M. Diesburg, J. Escada, R. Esteve, R. Felkai, L.M.P. Fernandes, et al (50)
May 30 2017 physics.ins-det hep-ex arXiv:1705.10270v1

@misc{1705.10270, author = {NEXT Collaboration and A.~Simón and C.~Lerche and F.~Monrabal and J.J.~Gómez-Cadenas and V.~Álvarez and C.D.R.~Azevedo and J.M.~Benlloch-Rodríguez and F.I.G.M.~Borges and A.~Botas and S.~Cárcel and J.V.~Carrión and S.~Cebrián and C.A.N.~Conde and J.~Díaz and M.~Diesburg and J.~Escada and R.~Esteve and R.~Felkai and L.M.P.~Fernandes and P.~Ferrario and A.L.~Ferreira and E.D.C.~Freitas and A.~Goldschmidt and D.~González-Díaz and R.M.~Gutiérrez and J.~Hauptman and C.A.O.~Henriques and A.I.~Hernandez and J.A.~Hernando Morata and V.~Herrero and B.J.P.~Jones and L.~Labarga and A.~Laing and P.~Lebrun and I.~Liubarsky and N.~López-March and M.~Losada and J.~Martín-Albo and G.~Martínez-Lema and A.~Martínez and A.D.~McDonald and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and J.~Muñoz Vidal and M.~Musti and M.~Nebot-Guinot and P.~Novella and D.R.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and J.~Renner and L.~Ripoll and J.~Rodríguez and L.~Rogers and F.P.~Santos and J.M.F.~dos Santos and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali}, title = {{A}pplication and performance of an {ML}-{EM} algorithm in {NEXT}}, year = {2017}, eprint = {1705.10270}, note = {arXiv:1705.10270v1} }
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The goal of the NEXT experiment is the observation of neutrinoless double beta decay in $^{136}$Xe using a gaseous xenon TPC with electroluminescent amplification and specialized photodetector arrays for calorimetry and tracking. The NEXT Collaboration is exploring a number of reconstruction algorithms to exploit the full potential of the detector. This paper describes one of them: the Maximum Likelihood Expectation Maximization (ML-EM) method, a generic iterative algorithm to find maximum-likelihood estimates of parameters that has been applied to solve many different types of complex inverse problems. In particular, we discuss a bi-dimensional version of the method in which the photosensor signals integrated over time are used to reconstruct a transverse projection of the event. First results show that, when applied to detector simulation data, the algorithm achieves nearly optimal energy resolution (better than 0.5% FWHM at the Q value of $^{136}$Xe) for events distributed over the full active volume of the TPC.
First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process
Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (200)
Apr 04 2017 hep-ex hep-ph arXiv:1704.00488v1

@misc{1704.00488, author = {Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and Z.~Kral and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.~Kveton and A.A.~Lednev and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rogacheva and M.~Roskot and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and A.~Thiel and J.~Tomsa and F.~Tosello and V.~Tskhay and S.~Uhl and A.~Vauth and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki}, title = {{F}irst measurement of transverse-spin-dependent azimuthal asymmetries in the {D}rell-{Y}an process}, year = {2017}, eprint = {1704.00488}, note = {arXiv:1704.00488v1} }
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The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/$c$, $\pi^{-}$ beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/$c^2$ and 8.5 GeV/$c^2$. The observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of Quantum Chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. These DY results are obtained at a hard scale comparable to that of a recent COMPASS SIDIS measurement and hence allow unique tests of fundamental QCD universality predictions.
First measurement of the Sivers asymmetry for gluons from SIDIS data
C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, et al (207)
Jan 11 2017 hep-ex hep-ph arXiv:1701.02453v1

@misc{1701.02453, author = {C.~Adolph and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and A.~Antoshkin and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rogacheva and M.~Roskot and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and A.~Thiel and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki and A.~Zink}, title = {{F}irst measurement of the {S}ivers asymmetry for gluons from {SIDIS} data}, year = {2017}, eprint = {1701.02453}, note = {arXiv:1701.02453v1} }
PDF
The Sivers function describes the correlation between the transverse spin of a nucleon and the transverse motion of its partons. It was extracted from measurements of the azimuthal asymmetry of hadrons produced in semi-inclusive deep inelastic scattering of leptons off transversely polarised nucleon targets, and it turned out to be non-zero for quarks. In this letter the evaluation of the Sivers asymmetry for gluons in the same process is presented. The analysis method is based on a Monte Carlo simulation that includes three hard processes: photon-gluon fusion, QCD Compton scattering and leading-order virtual-photon absorption process. The Sivers asymmetries of the three processes are simultaneously extracted using the LEPTO event generator and a neural network approach. The method is applied to samples of events containing at least two hadrons with large transverse momentum from the COMPASS data taken with a 160 GeV/$c$ muon beam scattered off transversely polarised deuterons and protons. With a significance of more than two standard deviations a negative value is obtained for the gluon Sivers asymmetry. The result of a similar analysis for a Collins-like asymmetry for gluons is consistent with zero.
Final COMPASS results on the deuteron spin-dependent structure function $g_1^{\rm d}$ and the Bjorken sum rule
C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (207)
Dec 05 2016 hep-ex arXiv:1612.00620v1

@misc{1612.00620, author = {C.~Adolph and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and A.~Kerbizi and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and A.~Thiel and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and R.~Windmolders and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki and A.~Zink}, title = {{F}inal {COMPASS} results on the deuteron spin-dependent structure function $g_1^{\rm d}$ and the {B}jorken sum rule}, year = {2016}, eprint = {1612.00620}, note = {arXiv:1612.00620v1} }
PDF
Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a $^6$LiD target. The data were taken at $160~{\rm GeV}$ beam energy and the results are shown for the kinematic range $1~({\rm GeV}/c)^2 < Q^2 < 100~({\rm GeV}/c)^2$ in photon virtuality, $0.004<x<0.7$ in the Bjorken scaling variable and $W > 4~{\rm GeV}/c^2$ in the mass of the hadronic final state. The deuteron double-spin asymmetry $A_1^{\rm d}$ and the deuteron longitudinal-spin structure function $g_1^{\rm d}$ are presented in bins of $x$ and $Q^2$. Towards lowest accessible values of $x$, $g_1^{\rm d}$ decreases and becomes consistent with zero within uncertainties. The presented final $g_1^{\rm d}$ values together with the recently published final $g_1^{\rm p}$ values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the $g_1$ world data at next-to-leading order of the strong coupling constant. In both cases, changes in central values of the resulting numbers are well within statistical uncertainties. The flavour-singlet axial charge $a_0$, which is identified in the $\overline{\rm MS}$ renormalisation scheme with the total contribution of quark helicities to the nucleon spin, is extracted from only the COMPASS deuteron data with negligible extrapolation uncertainty: $a_0 (Q^2 = 3~({\rm GeV}/c)^2) = 0.32 \pm 0.02_{\rm stat} \pm0.04_{\rm syst} \pm 0.05_{\rm evol}$. Together with the recent results on the proton spin structure function $g_1^{\rm p}$, the results on $g_1^{\rm d}$ constitute the COMPASS legacy on the measurements of $g_1$ through inclusive spin-dependent deep inelastic scattering.
Sivers asymmetry extracted in SIDIS at the hard scale of the Drell-Yan process at COMPASS
C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (207)
Sep 26 2016 hep-ex hep-ph arXiv:1609.07374v2

@misc{1609.07374, author = {C.~Adolph and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and C.~Elia and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and F.~Sozzi and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and A.~Thiel and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki and A.~Zink}, title = {{S}ivers asymmetry extracted in {SIDIS} at the hard scale of the {D}rell-{Y}an process at {COMPASS}}, year = {2016}, eprint = {1609.07374}, doi = {10.1016/j.physletb.2017.04.042}, note = {arXiv:1609.07374v2} }
PDF
Proton transverse-spin azimuthal asymmetries are extracted from the COMPASS 2010 semi-inclusive hadron measurements in deep inelastic muon-nucleon scattering in those four regions of the photon virtuality $Q^2$, which correspond to the four regions of the di-muon mass $\sqrt{Q^2}$ used in the ongoing analysis of the COMPASS Drell-Yan measurements. This allows for a future direct comparison of the nucleon transverse-momentum-dependent parton distribution functions extracted from these two alternative measurements. Various two-dimensional kinematic dependences are presented for the azimuthal asymmetries induced by the Sivers transverse-momentum-dependent parton distribution function. The integrated Sivers asymmetries are found to be positive with an accuracy that appears to be sufficient to test the sign change of the Sivers function predicted by Quantum Chromodynamics.
Background rejection in NEXT using deep neural networks
NEXT Collaboration, J. Renner, A. Farbin, J. Muñoz Vidal, J.M. Benlloch-Rodríguez, A. Botas, P. Ferrario, J.J. Gómez-Cadenas, V. Álvarez, C.D.R. Azevedo, F.I.G. Borges, S. Cárcel, J.V. Carrión, S. Cebrián, A. Cervera, C.A.N. Conde, J. Díaz, M. Diesburg, R. Esteve, L.M.P. Fernandes, et al (47)
Sep 21 2016 physics.ins-det hep-ex arXiv:1609.06202v3

@misc{1609.06202, author = {NEXT Collaboration and J.~Renner and A.~Farbin and J.~Muñoz Vidal and J.M.~Benlloch-Rodríguez and A.~Botas and P.~Ferrario and J.J.~Gómez-Cadenas and V.~Álvarez and C.D.R.~Azevedo and F.I.G.~Borges and S.~Cárcel and J.V.~Carrión and S.~Cebrián and A.~Cervera and C.A.N.~Conde and J.~Díaz and M.~Diesburg and R.~Esteve and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and A.~Goldschmidt and D.~González-Díaz and R.M.~Gutiérrez and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and V.~Herrero and B.~Jones and L.~Labarga and A.~Laing and P.~Lebrun and I.~Liubarsky and N.~López-March and D.~Lorca and M.~Losada and J.~Martín-Albo and G.~Martínez-Lema and A.~Martínez and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and M.~Nebot-Guinot and P.~Novella and D.~Nygren and A.~Para and J.~Pérez and M.~Querol and L.~Ripoll and J.~Rodríguez and F.P.~Santos and J.M.F.~dos Santos and L.~Serra and D.~Shuman and A.~Simón and C.~Sofka and M.~Sorel and J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and J.~White and R.~Webb and N.~Yahlali and H.~Yepes-Ramírez}, title = {{B}ackground rejection in {NEXT} using deep neural networks}, year = {2016}, eprint = {1609.06202}, note = {arXiv:1609.06202v3} }
PDF
We investigate the potential of using deep learning techniques to reject background events in searches for neutrinoless double beta decay with high pressure xenon time projection chambers capable of detailed track reconstruction. The differences in the topological signatures of background and signal events can be learned by deep neural networks via training over many thousands of events. These networks can then be used to classify further events as signal or background, providing an additional background rejection factor at an acceptable loss of efficiency. The networks trained in this study performed better than previous methods developed based on the use of the same topological signatures by a factor of 1.2 to 1.6, and there is potential for further improvement.
Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons
C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, et al (205)
Sep 21 2016 hep-ex hep-ph arXiv:1609.06062v2

@misc{1609.06062, author = {C.~Adolph and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and J.~Giarra and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and A.~Thiel and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki and A.~Zink}, title = {{A}zimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons}, year = {2016}, eprint = {1609.06062}, note = {arXiv:1609.06062v2} }
PDF
Single hadron azimuthal asymmetries of positive and negative hadrons produced in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also combined all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\phi$ is obtained by means of a five-parameter fitting function that besides a $\phi$-independent term includes four modulations predicted by theory: $\sin\phi$, $\sin 2 \phi$, $\sin 3\phi$ and $\cos\phi$. The amplitudes of the five terms have been extracted, first, for the hadrons in the whole available kinematic region. In further fits, performed for hadrons from a restricted kinematic region, the $\phi$-dependence is determined as a function of one of three variables (Bjorken-$x$, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the others. Except the $\phi$-independent term, all the modulation amplitudes are very small, and no clear kinematic dependence could be observed within experimental uncertainties.
Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target
C. Adolph, J. Agarwala, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, et al (207)
Aug 25 2016 hep-ex nucl-ex arXiv:1608.06760v1

@misc{1608.06760, author = {C.~Adolph and J.~Agarwala and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and K.~Augsten and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and M.~Ball and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and M.~Bodlak and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and L.~Capozza and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and Ch.~Dreisbach and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and G.~Hamar and D.~von Harrach and F.H.~Heinsius and R.~Heitz and F.~Herrmann and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and V.~Jary and R.~Joosten and P.~Joeorg and E.~Kabuss and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and A.~Nagaytsev and F.~Nerling and D.~Neyret and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and E.~Seder and A.~Selyunin and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and A.~Srnka and D.~Steffen and M.~Stolarski and O.~Subrt and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and A.~Thiel and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and R.~Windmolders and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and N.~Zhuravlev and M.~Ziembicki and A.~Zink}, title = {{M}ultiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target}, year = {2016}, eprint = {1608.06760}, note = {arXiv:1608.06760v1} }
PDF
Precise measurements of charged-kaon multiplicities in deep inelastic scattering were performed. The results are presented in three-dimensional bins of the Bjorken scaling variable x, the relative virtual-photon energy y, and the fraction z of the virtual-photon energy carried by the produced hadron. The data were obtained by the COMPASS Collaboration by scattering 160 GeV muons off an isoscalar 6 LiD target. They cover the kinematic domain 1 (GeV/c)2 < Q2 < 60 (GeV/c)^2 in the photon virtuality, 0.004 < x < 0.4, 0.1 < y < 0.7, 0.20 < z < 0.85, and W > 5 GeV/c^2 in the invariant mass of the hadronic system. The results from the sum of the z-integrated K+ and K- multiplicities at high x point to a value of the non-strange quark fragmentation function larger than obtained by the earlier DSS fit.
In-beam evaluation of a medium-size Resistive-Plate WELL gaseous particle detector
L. Moleri, F. D. Amaro, L. Arazi, C. D. R. Azevedo, A. Breskin, A. E. C. Coimbra, E. Oliveri, F. A. Pereira, D. Shaked Renous, J. Schaarschmidt, J. M. F. dos Santos, J. F. C. A. Veloso, S. Bressler
Jul 12 2016 physics.ins-det hep-ex arXiv:1607.02587v2

@misc{1607.02587, author = {L.~Moleri and F.~D.~Amaro and L.~Arazi and C.~D.~R.~Azevedo and A.~Breskin and A.~E.~C.~Coimbra and E.~Oliveri and F.~A.~Pereira and D.~Shaked Renous and J.~Schaarschmidt and J.~M.~F.~dos Santos and J.~F.~C.~A.~Veloso and S.~Bressler}, title = {{I}n-beam evaluation of a medium-size {R}esistive-{P}late {WELL} gaseous particle detector}, year = {2016}, eprint = {1607.02587}, note = {arXiv:1607.02587v2} }
PDF
In-beam evaluation of a fully-equipped medium-size 30$\times$30 cm$^2$ Resistive Plate WELL (RPWELL) detector is presented. It consists here of a single element gas-avalanche multiplier with Semitron ESD225 resistive plate, 1 cm$^2$ readout pads and APV25/SRS electronics. Similarly to previous results with small detector prototypes, stable operation at high detection efficiency (>98%) and low average pad multiplicity (~1.2) were recorded with 150 GeV muon and high-rate pion beams, in Ne/(5%CH$_4$), Ar/(5%CH$_4$) and Ar/(7%CO$_2$). This is an important step towards the realization of robust detectors suitable for applications requiring large-area coverage; among them Digital Hadron Calorimetry.
Exclusive $\omega$ meson muoproduction on transversely polarised protons
C. Adolph, J. Agarwala, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, et al (209)
Jun 14 2016 hep-ex nucl-ex arXiv:1606.03725v2

@misc{1606.03725, author = {C.~Adolph and J.~Agarwala and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and J.~Bisplinghoff and M.~Bodlak and M.~Boer and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and D.~von Harrach and R.~Hashimoto and F.H.~Heinsius and R.~Heitz and F.~Herrmann and F.~Hinterberger and N.~Horikawa and N.~dHose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and R.~Jahn and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and Y.-S.~Lian and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and M.~Meyer and W.~Meyer and T.~Michigami and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and P.~Montuenga and A.~Nagaytsev and F.~Nerling and D.~Neyret and V.I.~Nikolaenko and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and N.~Pierre and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and S.~Schopferer and E.~Seder and A.~Selyunin and O.Yu.~Shevchenko and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and F.~Sozzi and A.~Srnka and D.~Steffen and M.~Stolarski and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and S.~Wallner and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki and A.~Zink}, title = {{E}xclusive $\omega$ meson muoproduction on transversely polarised protons}, year = {2016}, eprint = {1606.03725}, doi = {10.1016/j.nuclphysb.2016.12.015}, note = {arXiv:1606.03725v2} }
PDF
Exclusive production of $\omega$ mesons was studied at the COMPASS experiment by scattering $160~\mathrm{GeV}/\mathit{c}$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality $1~(\mathrm{GeV}/\mathit{c})^2 < Q^2 < 10~(\mathrm{GeV}/\mathit{c})^2$, Bjorken scaling variable $0.003 < x_{\mathit{Bj}} < 0.3$ and transverse momentum squared of the $\omega$ meson $0.05~(\mathrm{GeV}/\mathit{c})^2 < p_{T}^{2} < 0.5~(\mathrm{GeV}/\mathit{c})^2$. The measured asymmetries are sensitive to the nucleon helicity-flip Generalised Parton Distributions (GPD) $E$ that are related to the orbital angular momentum of quarks, the chiral-odd GPDs $H_{T}$ that are related to the transversity Parton Distribution Functions, and the sign of the $\pi\omega$ transition form factor. The results are compared to recent calculations of a GPD-based model.
Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target
C. Adolph, J. Agarwala, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, et al (208)
Apr 12 2016 hep-ex nucl-ex arXiv:1604.02695v2

@misc{1604.02695, author = {C.~Adolph and J.~Agarwala and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and J.~Bisplinghoff and M.~Bodlak and M.~Boer and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and L.~Capozza and W.-C.~Chang and C.~Chatterjee and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and D.~von Harrach and R.~Hashimoto and F.H.~Heinsius and R.~Heitz and F.~Herrmann and F.~Hinterberger and N.~Horikawa and N.~dHose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and R.~Jahn and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and R.~Kuhn and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and W.~Meyer and T.~Michigami and Yu.V.~Mikhailov and M.~Mikhasenko and E.~Mitrofanov and N.~Mitrofanov and Y.~Miyachi and P.~Montuenga and A.~Nagaytsev and F.~Nerling and D.~Neyret and V.I.~Nikolaenko and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and S.~Schopferer and E.~Seder and A.~Selyunin and O.Yu.~Shevchenko and D.~Steffen and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and F.~Sozzi and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and T.~Weisrock and M.~Wilfert and R.~Windmolders and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki and A.~Zink}, title = {{M}ultiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target}, year = {2016}, eprint = {1604.02695}, note = {arXiv:1604.02695v2} }
PDF
Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable $x$, the relative virtual-photon energy $y$ and the relative hadron energy $z$. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and an isoscalar target ($^6$LiD). They cover the kinematic domain in the photon virtuality $Q^2$ > 1(GeV/c$)^2$, $0.004 < x < 0.4$, $0.2 < z < 0.85$ and $0.1 < y < 0.7$. In addition, a leading-order pQCD analysis was performed using the pion multiplicity results to extract quark fragmentation functions.
The Resistive-Plate WELL with Argon mixtures - a robust gaseous radiation detector
L. Moleri, F.D. Amaro, L. Arazi, C.D.R. Azevedo, E. Oliveri, M. Pitt, J. Schaarschmidt, D. Shaked-Renous, J.M.F. dos Santos, J.F.C.A. Veloso, A. Breskin, S. Bressler
Mar 16 2016 physics.ins-det hep-ex arXiv:1603.04820v1

@misc{1603.04820, author = {L.~Moleri and F.D.~Amaro and L.~Arazi and C.D.R.~Azevedo and E.~Oliveri and M.~Pitt and J.~Schaarschmidt and D.~Shaked-Renous and J.M.F.~dos Santos and J.F.C.A.~Veloso and A.~Breskin and S.~Bressler}, title = {{T}he {R}esistive-{P}late {WELL} with {A}rgon mixtures - a robust gaseous radiation detector}, year = {2016}, eprint = {1603.04820}, note = {arXiv:1603.04820v1} }
PDF
A thin single-element THGEM-based, Resistive-Plate WELL (RPWELL) detector was operated with 150 GeV/c muon and pion beams in Ne/(5%CH$_4$), Ar/(5%CH$_4$) and Ar/(7%CO$_2$); signals were recorded with 1 cm$^2$ square pads and SRS/APV25 electronics. Detection efficiency values greater than 98% were reached in all the gas mixtures, at average pad multiplicity of 1.2. The use of the 10$^9$\Omegacm resistive plate resulted in a completely discharge-free operation also in intense pion beams. The efficiency remained essentially constant at 98-99% up to fluxes of $\sim$10$^4$Hz/cm$^2$, dropping by a few % when approaching 10$^5$ Hz/cm$^2$. These results pave the way towards cost-effective, robust, efficient, large-scale detectors for a variety of applications in future particle, astro-particle and applied fields. A potential target application is digital hadron calorimetry.
Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data
C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E. R. Bielert, et al (201)
Dec 17 2015 hep-ex hep-ph arXiv:1512.05053v2

@misc{1512.05053, author = {C.~Adolph and M.~Aghasyan and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and N.V.~Anfimov and V.~Anosov and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and J.~Bisplinghoff and M.~Bodlak and M.~Boer and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Buechele and W.-C.~Chang and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and V.~Duic and W.~Duennweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmueller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and D.~von Harrach and R.~Hashimoto and F.H.~Heinsius and R.~Heitz and F.~Herrmann and F.~Hinterberger and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and R.~Jahn and V.~Jary and R.~Joosten and P.~Joerg and E.~Kabuss and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Koenigsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.M.~Kouznetsov and M.~Kraemer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and Y.~Kulinich and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.V.~Meshcheryakov and W.~Meyer and T.~Michigami and Yu.V.~Mikhailov and M.~Mikhasenko and Y.~Miyachi and P.~Montuenga and A.~Nagaytsev and F.~Nerling and D.~Neyret and V.I.~Nikolaenko and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pesek and D.V.~Peshekhonov and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and M.~Roskot and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rybnikov and A.~Rychter and R.~Salac and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and T.~Sawada and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schoenning and S.~Schopferer and E.~Seder and A.~Selyunin and O.Yu.~Shevchenko and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and J.~Smolik and F.~Sozzi and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and M.~Tasevsky and S.~Tessaro and F.~Tessarotto and F.~Thibaud and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and J.~Vondra and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and P.~Zavada and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki and A.~Zink}, title = {{L}eading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data}, year = {2015}, eprint = {1512.05053}, note = {arXiv:1512.05053v2} }
PDF
Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_{\rm T}$, the different $p_{\rm T}$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\mu^2= \langle Q^2 \rangle = 3 ({\rm GeV}/c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_{\rm g}$, covering the range $0.04 \!<\! x_{ \rm g}\! <\! 0.28$~ and does not exhibit a significant dependence on $x_{\rm g}$. The average over the three intervals, $\langle \Delta g/g \rangle = 0.113 \pm 0.038_{\rm (stat.)}\pm 0.036_{\rm (syst.)}$ at $\langle x_{\rm g} \rangle \approx 0.10$, suggests that the gluon polarisation is positive in the measured $x_{\rm g}$ range.
Sensitivity of NEXT-100 to neutrinoless double beta decay
NEXT Collaboration, J. Martín-Albo, J. Muñoz Vidal, P. Ferrario, M. Nebot-Guinot, J.J. Gómez-Cadenas, V. Álvarez, C.D.R. Azevedo, F.I.G. Borges, S. Cárcel, S. Cebrián, A. Cervera, C.A.N. Conde, J. Díaz, M. Diesburg, R. Esteve, L.M.P. Fernandes, A.L. Ferreira, E.D.C. Freitas, A. Goldschmidt, et al (43)
Dec 01 2015 physics.ins-det hep-ex nucl-ex arXiv:1511.09246v2

@misc{1511.09246, author = {NEXT Collaboration and J.~Martín-Albo and J.~Muñoz Vidal and P.~Ferrario and M.~Nebot-Guinot and J.J.~Gómez-Cadenas and V.~Álvarez and C.D.R.~Azevedo and F.I.G.~Borges and S.~Cárcel and S.~Cebrián and A.~Cervera and C.A.N.~Conde and J.~Díaz and M.~Diesburg and R.~Esteve and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and A.~Goldschmidt and D.~González-Díaz and R.M.~Gutiérrez and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and L.~Labarga and A.~Laing and P.~Lebrun and I.~Liubarsky and N.~López-March and D.~Lorca and M.~Losada and G.~Martínez-Lema and A.~Martínez and F.~Monrabal and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and P.~Novella and D.~Nygren and B.~Palmeiro and A.~Para and J.~Pérez and M.~Querol and J.~Renner and L.~Ripoll and J.~Rodríguez and F.P.~Santos and J.M.F.~dos Santos and L.~Serra and D.~Shuman and A.~Simón and C.~Sofka and M.~Sorel and T.~Stiegler and J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and R.~Webb and J.T.~White and N.~Yahlali and H.~Yepes-Ramírez}, title = {{S}ensitivity of {NEXT}-100 to neutrinoless double beta decay}, year = {2015}, eprint = {1511.09246}, howpublished = {JHEP 1605 (2016) 159}, doi = {10.1007/JHEP05(2016)159}, note = {arXiv:1511.09246v2} }
PDF
NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta ($\beta \beta 0 \nu$) decay of Xe-136. The detector possesses two features of great value for $\beta \beta 0 \nu$ searches: energy resolution better than 1\% FWHM at the $Q$ value of Xe-136 and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most $4\times10^{-4}$ counts keV$^{-1}$ kg$^{-1}$ yr$^{-1}$. Accordingly, the detector will reach a sensitivity to the \bbonu-decay half-life of $2.8\times10^{25}$ years (90\% CL) for an exposure of 100 $\mathrm{kg}\cdot\mathrm{year}$, or $6.0\times10^{25}$ years after a run of 3 effective years.
An homeopathic cure to pure Xenon large diffusion
C. D. R. Azevedo, L.M.P. Fernandes, E. D. C. Freitas, D. Gonzalez-Diaz, F. Monrabal, C. M. B. Monteiro, J. M. F. Dos Santos, J.F.C.A. Veloso, J. J Gomez-Cadenas
Nov 24 2015 physics.ins-det hep-ex nucl-ex arXiv:1511.07189v1

@misc{1511.07189, author = {C.~D.~R.~Azevedo and L.M.P.~Fernandes and E.~D.~C.~Freitas and D.~Gonzalez-Diaz and F.~Monrabal and C.~M.~B.~Monteiro and J.~M.~F.~Dos Santos and J.F.C.A.~Veloso and J.~J Gomez-Cadenas}, title = {{A}n homeopathic cure to pure {X}enon large diffusion}, year = {2015}, eprint = {1511.07189}, note = {arXiv:1511.07189v1} }
PDF
The NEXT neutrinoless double beta decay experiment will use a high- pressure gas electroluminescence-based TPC to search for the decay of Xe-136. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qbb. The rejection potential associated to the topology reconstruction is limited by our capacity to prop- erly reconstruct the original path of the electrons in the gas. This reconstruction is limited by different factors that include the geometry of the detector, the density of the sensors in the tracking plane and the separation among them, etc. Ultimately, the resolution is limited by the physics of electron diffusion in the gas. In this paper we present a series of molecular additives that can be used in Xenon gas at very low partial pressure to reduce both longitudinal and transverse diffusion. We will show the results of different Monte-Carlo simulations of electron transport in the gas mixtures from wich we have extracted the value of some important parameters like diffusion, drift velocity and light yields. These results show that there is a series of candidates that can reduce diffusion without affecting the energy resolution of the detector and they should be studied experimentally. A comparison with preliminary results from such an ongoing experimental effort is given.
Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high $p_T$
COMPASS Collaboration, C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, et al (191)
Sep 14 2015 hep-ex hep-ph arXiv:1509.03526v2

@misc{1509.03526, author = {COMPASS Collaboration and C.~Adolph and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badełek and F.~Balestra and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.R.~Bielert and R.~Birsa and J.~Bisplinghoff and M.~Bodlak and M.~Boer and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Büchele and E.~Burtin and W.-C.~Chang and M.~Chiosso and I.~Choi and S.-U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and V.~Duic and W.~Dünnweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmüller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and D.~von Harrach and R.~Hashimoto and F.H.~Heinsius and F.~Herrmann and F.~Hinterberger and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and R.~Jahn and V.~Jary and R.~Joosten and P.~Jörg and E.~Kabuß and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Königsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.~Kouznetsov and M.~Krämer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and N.~Kuchinski and R.~Kuhn and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matoušek and H.~Matsuda and T.~Matsuda and G.~Meshcheryakov and W.~Meyer and T.~Michigami and Yu.V.~Mikhailov and Y.~Miyachi and P.~Montuenga and A.~Nagaytsev and F.~Nerling and D.~Neyret and V.I.~Nikolaenko and J.~Nový and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pešek and D.V.~Peshekhonov and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schönning and S.~Schopferer and A.~Selyunin and O.Yu.~Shevchenko and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and F.~Sozzi and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and S.~Tessaro and F.~Tessarotto and F.~Thibaud and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki and A.~Zink}, title = {{L}ongitudinal double spin asymmetries in single hadron quasi-real photoproduction at high $p_{T}$}, year = {2015}, eprint = {1509.03526}, note = {arXiv:1509.03526v2} }
PDF
We measured the longitudinal double spin asymmetries $A_{LL}$ for single hadron muo-production off protons and deuterons at photon virtuality $Q^2$ < 1(GeV/$\it c$)$^2$ for transverse hadron momenta $p_T$ in the range 0.7 GeV/$\it c$ to 4 GeV/$\it c$ . They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/$\it c$ or 200 GeV/$\it c$ impinging on polarised $\mathrm{{}^6LiD}$ or $\mathrm{NH_3}$ targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation $\Delta G$ inside the nucleon in the range of the nucleon momentum fraction carried by gluons $0.05 < x_g < 0.2$.
Resonance Production and $\pi\pi$ S-wave in $\pi^- + p \rightarrow \pi^- \pi^- \pi^+ + p_{recoil}$ at 190 GeV/c
C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, J. Bisplinghoff, et al (190)
Sep 04 2015 hep-ex hep-ph arXiv:1509.00992v2

@misc{1509.00992, author = {C.~Adolph and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badełek and F.~Balestra and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.R.~Bielert and R.~Birsa and J.~Bisplinghoff and M.~Bodlak and M.~Boer and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Büchele and E.~Burtin and W.-C.~Chang and M.~Chiosso and I.~Choi and S.U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and V.~Duic and W.~Dünnweber and M.~Dziewiecki and A.~Efremov and P.D.~Eversheim and W.~Eyrich and M.~Faessler and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmüller and A.~Grasso and M.~Grosse Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and D.~von Harrach and R.~Hashimoto and F.H.~Heinsius and F.~Herrmann and F.~Hinterberger and N.~Horikawa and N.~d'Hose and C.-Y.~Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and R.~Jahn and V.~Jary and R.~Joosten and P.~Jörg and E.~Kabuß and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Königsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.~Kouznetsov and M.~Krämer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and N.~Kuchinski and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matoušek and H.~Matsuda and T.~Matsuda and G.~Meshcheryakov and W.~Meyer and T.~Michigami and Yu.V.~Mikhailov and Y.~Miyachi and P.~Montuenga and A.~Nagaytsev and F.~Nerling and D.~Neyret and V.I.~Nikolaenko and J.~Nový and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and M.~Pešek and D.V.~Peshekhonov and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and P.~Schiavon and T.~Schlüter and K.~Schmidt and H.~Schmieden and K.~Schönning and S.~Schopferer and A.~Selyunin and O.Yu.~Shevchenko and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and F.~Sozzi and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and S.~Tessaro and F.~Tessarotto and F.~Thibaud and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and T.~Weisrock and M.~Wilfert and J.~ter Wolbeek and K.~Zaremba and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki and A.~Zink}, title = {{R}esonance {P}roduction and $\pi\pi$ {S}-wave in $\pi^- + p \rightarrow \pi^- \pi^- \pi^+ + p_{recoil}$ at 190 {G}e{V}/c}, year = {2015}, eprint = {1509.00992}, howpublished = {Phys. Rev. D 95, 032004 (2017)}, doi = {10.1103/PhysRevD.95.032004}, note = {arXiv:1509.00992v2} }
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The COMPASS collaboration has collected the currently largest data set on diffractively produced $\pi^-\pi^-\pi^+$ final states using a negative pion beam of 190 GeV/c momentum impinging on a stationary proton target. This data set allows for a systematic partial-wave analysis in 100 bins of three-pion mass, $0.5 < m_{3\pi} < 2.5$ GeV/c$^2$ , and in 11 bins of the reduced four-momentum transfer squared, $0.1 < t < 1.0$ (GeV/c)$^2$ . This two-dimensional analysis offers sensitivity to genuine one-step resonance production, i.e. the production of a state followed by its decay, as well as to more complex dynamical effects in nonresonant $3\pi$ production. In this paper, we present detailed studies on selected $3\pi$ partial waves with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{-+}$, $2^{++}$, and $4^{++}$. In these waves, we observe the well-known ground-state mesons as well as a new narrow axial-vector meson $a_1(1420)$ decaying into $f_0(980) \pi$. In addition, we present the results of a novel method to extract the amplitude of the $\pi^-\pi^+$ subsystem with $I^{G}J^{PC} = 0^+ 0^{++}$ in various partial waves from the $\pi^-\pi^-\pi^+$ data. Evidence is found for correlation of the $f_0(980)$ and $f_0(1500)$ appearing as intermediate $\pi^- \pi^+$ isobars in the decay of the known $\pi(1800)$ and $\pi_2(1880)$.
Interplay among transversity induced asymmetries in hadron leptoproduction
Compass Collaboration, C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badelek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E. R. Bielert, R. Birsa, et al (190)
Jul 29 2015 hep-ex hep-ph arXiv:1507.07593v2

@misc{1507.07593, author = {Compass Collaboration and C.~Adolph and R.~Akhunzyanov and M.G.~Alexeev and G.D.~Alexeev and A.~Amoroso and V.~Andrieux and V.~Anosov and W.~Augustyniak and A.~Austregesilo and C.D.R.~Azevedo and B.~Badelek and F.~Balestra and J.~Barth and R.~Beck and Y.~Bedfer and J.~Bernhard and K.~Bicker and E.~R.~Bielert and R.~Birsa and J.~Bisplinghoff and M.~Bodlak and M.~Boer and P.~Bordalo and F.~Bradamante and C.~Braun and A.~Bressan and M.~Büchele and E.~Burtin and W.-C.~Chang and M.~Chiosso and I.~Choi and S.U.~Chung and A.~Cicuttin and M.L.~Crespo and Q.~Curiel and N.~d'Hose and S.~Dalla Torre and S.S.~Dasgupta and S.~Dasgupta and O.Yu.~Denisov and L.~Dhara and S.V.~Donskov and N.~Doshita and V.~Duic and M.~Dziewiecki and A.~Efremov and C.~Elia and P.D.~Eversheim and W.~Eyrich and A.~Ferrero and M.~Finger and M.~Finger jr.~and H.~Fischer and C.~Franco and N.~du Fresne von Hohenesche and J.M.~Friedrich and V.~Frolov and E.~Fuchey and F.~Gautheron and O.P.~Gavrichtchouk and S.~Gerassimov and F.~Giordano and I.~Gnesi and M.~Gorzellik and S.~Grabmüller and A.~Grasso and M.~Grosse-Perdekamp and B.~Grube and T.~Grussenmeyer and A.~Guskov and F.~Haas and D.~Hahne and D.~von Harrach and R.~Hashimoto and F.H.~Heinsius and F.~Herrmann and F.~Hinterberger and N.~Horikawa and C.-Yu Hsieh and S.~Huber and S.~Ishimoto and A.~Ivanov and Yu.~Ivanshin and T.~Iwata and R.~Jahn and V.~Jary and P.~Jörg and R.~Joosten and E.~Kabuß and B.~Ketzer and G.V.~Khaustov and Yu.A.~Khokhlov and Yu.~Kisselev and F.~Klein and K.~Klimaszewski and J.H.~Koivuniemi and V.N.~Kolosov and K.~Kondo and K.~Königsmann and I.~Konorov and V.F.~Konstantinov and A.M.~Kotzinian and O.~Kouznetsov and M.~Krämer and P.~Kremser and F.~Krinner and Z.V.~Kroumchtein and N.~Kuchinski and F.~Kunne and K.~Kurek and R.P.~Kurjata and A.A.~Lednev and A.~Lehmann and M.~Levillain and S.~Levorato and J.~Lichtenstadt and R.~Longo and A.~Maggiora and A.~Magnon and N.~Makins and N.~Makke and G.K.~Mallot and C.~Marchand and B.~Marianski and A.~Martin and J.~Marzec and J.~Matousek and H.~Matsuda and T.~Matsuda and G.~Meshcheryakov and W.~Meyer and T.~Michigami and Yu.V.~Mikhailov and Y.~Miyachi and P.~Montuenga and A.~Nagaytsev and F.~Nerling and D.~Neyret and V.I.~Nikolaenko and J.~Novy and W.-D.~Nowak and G.~Nukazuka and A.S.~Nunes and A.G.~Olshevsky and I.~Orlov and M.~Ostrick and D.~Panzieri and B.~Parsamyan and S.~Paul and J.-C.~Peng and F.~Pereira and G.~Pesaro and M.~Pesek and D.V.~Peshekhonov and S.~Platchkov and J.~Pochodzalla and V.A.~Polyakov and J.~Pretz and M.~Quaresma and C.~Quintans and S.~Ramos and C.~Regali and G.~Reicherz and C.~Riedl and N.S.~Rossiyskaya and D.I.~Ryabchikov and A.~Rychter and V.D.~Samoylenko and A.~Sandacz and C.~Santos and S.~Sarkar and I.A.~Savin and G.~Sbrizzai and P.~Schiavon and K.~Schmidt and H.~Schmieden and K.~Schönning and S.~Schopferer and A.~Selyunin and O.Yu.~Shevchenko and L.~Silva and L.~Sinha and S.~Sirtl and M.~Slunecka and F.~Sozzi and A.~Srnka and M.~Stolarski and M.~Sulc and H.~Suzuki and A.~Szabelski and T.~Szameitat and P.~Sznajder and S.~Takekawa and J.~ter Wolbeek and S.~Tessaro and F.~Tessarotto and F.~Thibaud and F.~Tosello and V.~Tskhay and S.~Uhl and J.~Veloso and M.~Virius and T.~Weisrock and M.~Wilfert and K.~Zaremba and M.~Zavertyaev and E.~Zemlyanichkina and M.~Ziembicki and A.~Zink}, title = {{I}nterplay among transversity induced asymmetries in hadron leptoproduction}, year = {2015}, eprint = {1507.07593}, note = {arXiv:1507.07593v2} }
PDF
In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhibits an azimuthal modulation known as Collins effect. When a pair of oppositely charged hadrons is observed, three asymmetries can be considered, a di-hadron asymmetry and two single hadron asymmetries. In lepton deep inelastic scattering on transversely polarized nucleons all these asymmetries are coupled with the transversity distribution. From the high statistics COMPASS data on oppositely charged hadron-pair production we have investigated for the first time the dependence of these three asymmetries on the difference of the azimuthal angles of the two hadrons. The similarity of transversity induced single and di-hadron asymmetries is discussed. A new analysis of the data allows to establish quantitative relationships among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process.
First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment
NEXT Collaboration, P. Ferrario, A. Laing, N. López-March, J.J. Gómez-Cadenas, V. Álvarez, C.D.R. Azevedo, F.I.G. Borges, S. Cárcel, S. Cebrián, A. Cervera, C.A.N. Conde, T. Dafni, J. Díaz, M. Diesburg, R. Esteve, L.M.P. Fernandes, A.L. Ferreira, E.D.C. Freitas, V.M. Gehman, et al (50)
Jul 22 2015 physics.ins-det hep-ex arXiv:1507.05902v6

@misc{1507.05902, author = {NEXT Collaboration and P.~Ferrario and A.~Laing and N.~López-March and J.J.~Gómez-Cadenas and V.~Álvarez and C.D.R.~Azevedo and F.I.G.~Borges and S.~Cárcel and S.~Cebrián and A.~Cervera and C.A.N.~Conde and T.~Dafni and J.~Díaz and M.~Diesburg and R.~Esteve and L.M.P.~Fernandes and A.L.~Ferreira and E.D.C.~Freitas and V.M.~Gehman and A.~Goldschmidt and D.~González-Díaz and R.M.~Gutiérrez and J.~Hauptman and C.A.O.~Henriques and J.A.~Hernando Morata and I.G.~Irastorza and L.~Labarga and P.~Lebrun and I.~Liubarsky and D.~Lorca and M.~Losada and G.~Luzón and A.~Marí and J.~Martín-Albo and G.~Martínez-Lema and A.~Martínez and T.~Miller and F.~Monrabal and M.~Monserrate and C.M.B.~Monteiro and F.J.~Mora and L.M.~Moutinho and J.~Muñoz Vidal and M.~Nebot-Guinot and P.~Novella and D.~Nygren and A.~Para and J.~Pérez and J.L.~Pérez Aparicio and M.~Querol and J.~Renner and L.~Ripoll and J.~Rodríguez and F.P.~Santos and J.M.F.~dos Santos and L.~Serra and D.~Shuman and A.~Simón and C.~Sofka and M.~Sorel and J.F.~Toledo and J.~Torrent and Z.~Tsamalaidze and J.F.C.A.~Veloso and J.A.~Villar and R.~Webb and J.T.~White and N.~Yahlali and H.~Yepes-Ramírez}, title = {{F}irst proof of topological signature in the high pressure xenon gas {TPC} with electroluminescence amplification for the {NEXT} experiment}, year = {2015}, eprint = {1507.05902}, note = {arXiv:1507.05902v6} }
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The NEXT experiment aims to observe the neutrinoless double beta decay of xenon in a high-pressure Xe136 gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qbb. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype. Single electrons resulting from the interactions of Na22 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the Th228 decay chain were used to represent the background and the signal in a double beta decay. These data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 +- 1.4 (stat.)%, while maintaining an efficiency of 66.7 +- 1% for signal events.