The $η^\prime$ Photoproduction off the Nucleon in the quark model

Abstract

The reaction $γ+ p\to η^\prime + p$ is investigated in the quark model approach. The quark model predicts that the off-shell contributions from the resonance $S_{11}(1535)$ dominate the $\etap$ production in the threshold region. We find that the coulping constant $α_{\etap NN}$ from the fit to a few total cross section data is small. The results of the total and differential cross sections are presented at different energies, which can be tested in the future experiments. If the future total cross data indeed show a resonance structure around 2 GeV suggested in a recent study, it would be an evidence of a non $qqq$ structure in its wavefunction.