First Measurements of ${\chi }_{cJ}\to {\mathrm{\Sigma }}^{-}{\bar{\mathrm{\Sigma }}}^{+}(J=0,1,2)$ Decays

We measured the branching fractions of the decays ${\chi }_{cJ}\to {\mathrm{\Sigma }}^{-}{\bar{\mathrm{\Sigma }}}^{+}$ for the first time using the final states $n\bar{n}{\pi }^{+}{\pi }^{-}$. The data sample exploited here is $448.1\times {10}^6$ $\psi (3686)$ events collected with BESIII. We find $$\mathcal{B}$(\chi_{cJ}\rightarrow\Sigma^{-}\bar{\Sigma}^{+}) = (51.3\pm2.4\pm4.1)\times10^{-5},, (5.7\pm1.4\pm0.6)\times10^{-5},, \rm{and}~ (4.4\pm1.7\pm0.5)\times10^{-5}$,for$J=0,1,2$, respectively, where the first uncertainties are statistical and the second systematic.