Study ofη production in two-photon collisions

Production of theη c meson ine + e − quasireal two photon collisions has been looked for in three channels. The data were obtained from an integrated luminosity of 189 pb−1. Anη c signal is observed in two decay modes (K 0 K ±π∓,π+π-π+π-) with a combined statistical significance of 3.5 standard deviations. Using the knownη c branching ratios to these channels and toK + K -π+π- the combined partialη c width to γγ isΓ γγ(η c ). The first error is statistical, and the second one includes the systematic and branching ratio errors. Calculated as an upper limit we obtainΓ γγ(η c ) (95% C.L., including the systematic error).