Comprehensive measurement of $\eta^\prime$ photoproduction off the proton at $E_\gamma < 2.4$ $\mathrm{GeV}$

TL;DR

This paper presents comprehensive measurements of $ ext{η}^ ext{'}$ photoproduction off protons, providing new data on photon beam asymmetries and cross sections that improve understanding of nucleon resonances and meson-nucleon interactions.

Contribution

It offers the first photon beam asymmetry measurements at energies above 1.84 GeV and the most precise differential cross sections at backward angles, enhancing amplitude analysis constraints.

Findings

Photon beam asymmetries measured at $E_γ > 1.84$ GeV.

Most precise differential cross sections at backward angles.

Indications of a larger $ ext{η}^ ext{'}$-nucleon coupling to the $N(2250)$ resonance.

Abstract

For the spectroscopy of nucleon resonances at the total energies from the $\eta^\prime$-meson production threshold to $2.32$ $\mathrm{GeV}$, photon beam asymmetries of the reaction $\gamma p \to \eta^\prime p$ were measured together with total and differential cross sections by analyzing the two decay modes $\eta^\prime \to \gamma \gamma$ and $\pi^0 \pi^0 \eta$. New constraints for amplitude decomposition were given by the first-time result of photon beam asymmetries at $E_\gamma > 1.84$ $\mathrm{GeV}$ and the most precise data of differential cross sections to date at extremely backward $\eta^\prime$ angles. The possibility of a larger coupling constant of the $\eta^\prime$-nucleon system to the $N(2250)$ resonance was implied in the partial wave analyses using the present data.