Analysis of the differential cross section and photon beam asymmetry data for $γp \to η^\prime p$

Abstract

The photoproduction reaction of γp → η ′ p is investigated based on an effective Lagrangian approach in the tree-level approximation, with the purpose being to understand the reaction mechanisms and to extract the resonance contents and the associated resonance parameters in this reaction. Apart from the t-channel ρ and ω exchanges, s-and u-channel nucleon exchanges, and generalized contact term, the exchanges of a minimum number of nucleon resonances in the s channel are taken into account in constructing the reaction amplitudes to describe the experimental data. It is found that a satisfactory description of the available data on both differential cross sections and photon beam asymmetries can be obtained by including in the s channel the exchanges of the N (1875)3/2 − and N (2040)3/2 + resonances. The reaction mechanisms of γp → η ′ p are discussed and a prediction for the target nucleon asymmetries is presented.