$\eta'$ photoproduction on the nucleons in the quark model

TL;DR

This paper uses a chiral quark-model to analyze $ ext{η'}$ photoproduction on nucleons, successfully explaining recent experimental data and identifying key resonances influencing the process.

Contribution

It introduces a detailed quark-model analysis of $ ext{η'}$ photoproduction, revealing the significance of the $D_{15}(2080)$ resonance and clarifying the roles of various nucleon resonances.

Findings

Identification of $D_{15}(2080)$ resonance as responsible for the bump at $W=2.1$ GeV.

Good agreement with CLAS and CBELSA/TAPS data.

Limited evidence for other high-mass resonances around 2.0 GeV.

Abstract

A chiral quark-model approach is adopted to study the $\gamma p\rightarrow \eta'p$ and $\gamma n\rightarrow \eta' n$. Good descriptions of the recent observations from CLAS and CBELSA/TAPS are obtained. Both of the processes are governed by $S_{11}(1535)$ and $u$ channel background. Strong evidence of an $n=3$ shell resonance $D_{15}(2080)$ is found in the reactions, which accounts for the bump-like structure around $W=2.1$ GeV observed in the total cross section and excitation functions at very forward angles. The $S_{11}(1920)$ seems to be needed in the reactions, with which the total cross section near threshold for the $\gamma p\rightarrow \eta' p$ is improved slightly. The polarized beam asymmetries show some sensitivities to $D_{13}(1520)$, although its effects on the differential cross sections and total cross sections are negligible. There is no obvious evidence of the $P$-, $D_{13}$-, $F$- and $G$-wave resonances with a mass around 2.0 GeV in the reactions.