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

Abstract

A search for the production of the $η'_c$ meson, the first radial excitation of the ground state of charmonium $η_c$(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 $η'_c$ 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 $η'_c$ and $η_c$ is obtained.