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

Abstract

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