The near-threshold peak of the φ-photoproduction cross section and its interpretation

We study, within phenomenological Lagrangian approach, the possibility that the near-threshold peak found in the φ-photoproduction cross section is caused by a resonance. We show that, by employing a $JP = 3/2−$ resonance with a mass of 2.08 ± 0.05 GeV and a width of 0.570 ± 0.169 GeV, the LEPS data which include new data on nine spin-density matrix elements can indeed be described reasonably well. We also find that the ratio of helicity amplitudes A_1/2/A_3/2 calculated fromthe resulting coupling constants differs in sign fromthat of D₁₃ (2080). The resonance is further found to be able to improve the theoretical description of ω photoproduction against a new set of data if a large value for OZI evading parameter is assumed.