\psi(2S) Decays into $\J$ plus Two Photons

Abstract

Using $\gamma \gamma J/\psi, J/\psi \ra e^+ e^-$ and $\mu^+ \mu^-$ events from a sample of $14.0\times 10^6$ $\psip$ decays collected with the BESII detector, the branching fractions for $\psip\ra \pi^0\J$, $\eta\J$, and $\psi(2S)\ar\gamma\chi_{c1},\gamma\chi_{c2}\ar\gamma\gamma\jpsi$ are measured to be $B(\psip\ra \pi^0\J) = (1.43\pm0.14\pm0.13)\times 10^{-3}$, $B(\psip\ra \eta\J) = (2.98\pm0.09\pm0.23)%$, $B(\psi(2S)\ar\gamma\chi_{c1}\ar\gamma\gamma\jpsi) = (2.81\pm0.05\pm 0.23)%$, and $B(\psi(2S)\ar\gamma\chi_{c2}\ar\gamma\gamma\jpsi) = (1.62\pm0.04\pm 0.12)%$.