Dergi makalesi Açık Erişim

Observation of ${\chi }_{cJ}\to \Lambda \overline{\Lambda }\eta $

2022    CERN İşbirliği

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