Observation of J/ψ→γηπ0

Le résumé fourni par la source

We present the first study of the process $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\eta}{\ensuremath{\pi}}^{0}$ using $(223.7\ifmmode\pm\else\textpm\fi{}1.4)\ifmmode\times\else\texttimes\fi{}1{0}^{6}$ $J/\ensuremath{\psi}$ events accumulated with the BESIII detector at the BEPCII facility. The branching fraction for $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\eta}{\ensuremath{\pi}}^{0}$ is measured to be $\mathcal{B}(J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\eta}{\ensuremath{\pi}}^{0})=(2.14\ifmmode\pm\else\textpm\fi{}0.18(\text{stat})\ifmmode\pm\else\textpm\fi{}0.25(\text{syst}))\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}5}$. With a Bayesian approach, the upper limits of the branching fractions $\mathcal{B}(J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}{a}_{0}(980),{a}_{0}(980)\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\pi}}^{0})$ and $\mathcal{B}(J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}{a}_{2}(1320),{a}_{2}(1320)\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\pi}}^{0})$ are determined to be $2.5\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}6}$ and $6.6\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}6}$ at the 95% confidence level, respectively. All of these measurements are given for the first time.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.