Search for ηc(2S)hc→pp¯ decays and measurements of the χcJ→pp¯ branching fractions

Le résumé fourni par la source

Using a sample of $1.06\ifmmode\times\else\texttimes\fi{}{10}^{8}\ensuremath{\psi}(3686)$ events collected with the BESIII detector at BEPCII, the decays ${\ensuremath{\eta}}_{c}(2S)\ensuremath{\rightarrow}p\overline{p}$ and ${h}_{c}\ensuremath{\rightarrow}p\overline{p}$ are searched for, where ${\ensuremath{\eta}}_{c}(2S)$ and ${h}_{c}$ are reconstructed in the decay chains $\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}(2S)$, ${\ensuremath{\eta}}_{c}(2S)\ensuremath{\rightarrow}p\overline{p}$ and $\ensuremath{\psi}(3686)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{h}_{c}$, ${h}_{c}\ensuremath{\rightarrow}p\overline{p}$, respectively. No significant signals are observed. The upper limits of the product branching fractions are determined to be $\mathcal{B}(\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}(2S))\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\ensuremath{\eta}}_{c}(2S)\ensuremath{\rightarrow}p\overline{p})<1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ and $\mathcal{B}(\ensuremath{\psi}(3686)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{h}_{c})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({h}_{c}\ensuremath{\rightarrow}p\overline{p})<1.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ at the 90% C.L.. The branching fractions for ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}p\overline{p}$ ($J=0$, 1, 2) are also measured to be $(24.5\ifmmode\pm\else\textpm\fi{}0.8\ifmmode\pm\else\textpm\fi{}1.3,8.6\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.5,8.4\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$, which are the world's most precise measurements.

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