Using $\gamma \gamma J/\psi ,J/\overrightarrow{\psi }{e}^{+}{e}^{-}$ and ${\mu }^{+}{\mu }^{-}$ events from a sample of $14.0\times {10}^6$ $\psi \mathrm{}\left(2S\right)\mathrm{}$ decays collected with the BESII detector, the branching fractions for $\psi \mathrm{}\left(2S\right)\mathrm{}\to {\pi }^{0}J/\psi ,$ $\eta J/\psi ,$ and $\psi \mathrm{}\left(2S\right)\mathrm{}\to \gamma {\chi }_{c1\mathrm{}},\gamma {\chi }_{c2\mathrm{}}\to \gamma \gamma J/\psi$ are measured to be $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to {\pi }^{0}J/\psi ]=(1.43\mathrm{}\pm 0.14\pm 0.12)\times {10}^{-3},$ $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to \eta J/\psi ]=(2.98\mathrm{}\pm 0.09\pm 0.23)\%,$ $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to \gamma {\chi }_{c1\mathrm{}}\to \gamma \gamma J/\psi ]=(2.81\mathrm{}\pm 0.05\pm 0.23)\%,$ and $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to \gamma {\chi }_{c2\mathrm{}}\to \gamma \gamma J/\psi ]=(1.62\mathrm{}\pm 0.04\pm 0.12)\%.$

• Received 14 March 2004

DOI:https://doi.org/10.1103/PhysRevD.70.012006