Search for the process $\mathbf{\it e^+e^-\to\eta^{\prime}\gamma}$ in the energy range $\mathbf{\it \sqrt{s}}$ = 1.075 -- 2 GeV

TL;DR

This study searches for the process e+e- to eta' gamma in the energy range 1.075 to 2 GeV using data from the VEPP-2000 collider, setting upper limits on the cross section due to no significant detection.

Contribution

First search for e+e- to eta' gamma in this energy range with new data, establishing upper limits on the process cross section.

Findings

No significant signal observed, upper limits set at 13 pb.

Data analyzed with 746 pb^-1 luminosity from 2010-2024.

Constraints improve understanding of eta' production in e+e- collisions.

Abstract

The results of the search for the $e^+e^-\to\eta^{\prime}\gamma$ process in the center-of-mass energy range from 1.075 to 2 GeV are presented. We analyze data with an integral luminosity of 746 pb$^{-1}$ accumulated with the SND detector at the $e^+e^-$ collider VEPP-2000 in 2010--2024. The $\eta^{\prime}\to\eta\pi^0\pi^0$ decay is used in the analysis, with the subsequent $\eta$ and $\pi^0$ decays into $\gamma\gamma$. Upper limits not exceeding 13 pb have been set on the $e^+e^-\to\eta^{\prime}\gamma$ cross section at the 90\% confidence level.