Observation ofpp¯π0andpp¯ηinψ′decays

The processes ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\rightarrow}p\overline{p}{\ensuremath{\pi}}^{0}$ and ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\rightarrow}p\overline{p}\ensuremath{\eta}$ are studied using a sample of $14\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${\ensuremath{\psi}}^{\ensuremath{'}}$ decays collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider. The branching fraction of ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\rightarrow}p\overline{p}{\ensuremath{\pi}}^{0}$ is measured with improved precision as $(13.2\ifmmode\pm\else\textpm\fi{}1.0\ifmmode\pm\else\textpm\fi{}1.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$, and ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\rightarrow}p\overline{p}\ensuremath{\eta}$ is observed for the first time with a branching fraction of $(5.8\ifmmode\pm\else\textpm\fi{}1.1\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$, where the first errors are statistical and the second ones are systematic.