First Measurements of $\ddot{I}{‡}_{cJ}\to \hat{I}{\pounds }^{-}\bar{\hat{I}}{\pounds }^{+}(J=0,1,2)$ Decays

Abstract

We measured the branching fractions of the decays $\ddot{I}{‡}_{cJ}\to \hat{I}{\pounds }^{-}\bar{\hat{I}}{\pounds }^{+}$ for the first time using the final states $n\bar{n}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$. The data sample exploited here is $448.1\times 10^6$ $\ddot{I}ˆ(3686)$ events collected with BESIII. We find $\mathcal{B}(\ddot{I}{‡}_{cJ}\to \hat{I}{\pounds }^{-}\bar{\hat{I}}{\pounds }^{+})=(51.3\pm 2.4\pm 4.1)\times 10^{-5},(5.7\pm 1.4\pm 0.6)\times 10^{-5},\mathrm{and}(4.4\pm 1.7\pm 0.5)\times 10^{-5}$, for $J=0,1,2$, respectively, where the first uncertainties are statistical and the second systematic.