Observation of χcJ→ΛΛ¯η

Le résumé fourni par la source

By analyzing $(448.1\ifmmode\pm\else\textpm\fi{}2.9)\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }\ensuremath{\psi}(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays of ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}\overline{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\eta}$ ($J=0$, 1, and 2) are observed for the first time with statistical significances of $13.9\ensuremath{\sigma}$, $6.7\ensuremath{\sigma}$, and $8.2\ensuremath{\sigma}$, respectively. The product branching fractions of $\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{cJ}$ and ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}\overline{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\eta}$ are measured. Dividing by the world averages of the branching fractions of $\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\phantom{\rule{0ex}{0ex}}\ensuremath{\gamma}{\ensuremath{\chi}}_{cJ}$, the branching fractions of ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}\overline{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\eta}$ decays are determined to be $(2.31\ifmmode\pm\else\textpm\fi{}0.30\ifmmode\pm\else\textpm\fi{}0.21)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, $(5.86\ifmmode\pm\else\textpm\fi{}1.38\ifmmode\pm\else\textpm\fi{}0.68)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$, and $(1.05\ifmmode\pm\else\textpm\fi{}0.21\ifmmode\pm\else\textpm\fi{}0.15)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ for $J=0$, 1 and 2, respectively, where the first uncertainties are statistical and the second systematic.

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