A Search for $\eta'_c$ Production in Photon-Photon Fusion at LEP

TL;DR

This study searched for the $'_c$ meson in photon-photon fusion at LEP but found no evidence, setting upper limits on its production relative to the $_c$ meson, contributing to understanding charmonium states.

Contribution

First search for $'_c$ production in photon-photon fusion at LEP, providing upper limits on its two-photon decay width ratio.

Findings

No evidence of $'_c$ production was observed.

An upper limit for the ratio of two-photon widths of $'_c$ and $_c$ was established.

Data collected by DELPHI during 1992-1996 was used.

Abstract

A search for the production of the $\eta'_c$ meson, the first radial excitation of the ground state of charmonium $\eta_c$(2980), in the photon-photon fusion reaction at LEP has been performed using the data collected by the DELPHI detector during 1992-1996. No evidence of $\eta'_c$ production is found in the mass region 3520--3800 MeV/c^2. An upper limit for the ratio of the two-photon widths of the $\eta'_c$ and $\eta_c$ is obtained.