Branching Fractions for $\psi (2S)to\gamma {\eta }^{\prime }$ and $\gamma \eta$

J. Z. Bai

We report the first measurements of the branching fractions: $B(\psi (2S)->\gamma {\eta }^{\prime })=(1.54\pm 0.31\pm 0.23)x10^{-4}$ and $B(\psi (2S)->\gamma \eta )=(0.53\pm 0.31\pm 0.08)x10^{-4}$. The $…