Abstract
Data for pion photo-productions off the neutron (\(\gamma n\rightarrow \pi N\)) have been primarily extracted from deuteron-target data (\(\gamma d\rightarrow \pi NN\)) by applying kinematical cuts thereby isolating the quasi-free samples. We critically examine if the neutron-target data obtained through this conventional procedure can be contaminated by final state interactions (FSI) and/or the kinematical cuts. The analysis is conducted with a theoretical model for \(\gamma d\rightarrow \pi NN\) that takes account of the impulse mechanisms supplemented by the NN and \(\pi N\) rescattering mechanisms. We show that the FSI effects still visibly remain in the extracted \(\gamma \)‘n’\(\rightarrow \pi N\) unpolarized cross sections and polarization asymmetries E even after the kinematical cuts are applied. We also find the FSI effects on \(\gamma \)‘n’\(\rightarrow \pi ^0n\) can be somewhat different from those on \(\gamma \)‘p’\(\rightarrow \pi ^0p\).
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This article belongs to the Topical Collection “NSTAR 2017—The International Workshop on the Physics of Excited Nucleons”.
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Nakamura, S.X. Photo- and Electro-excitation of Bound Neutrons and Protons. Few-Body Syst 59, 81 (2018). https://doi.org/10.1007/s00601-018-1404-9
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DOI: https://doi.org/10.1007/s00601-018-1404-9