Observation of the $\ddot{I}ˆ(3686)$ decays into $\hat{I}{\pounds }^{+}\bar{\hat{I}}{\pounds }^{-}\ddot{I}‰$ and $\hat{I}{\pounds }^{+}\bar{\hat{I}}{\pounds }^{-}\ddot{\mathcal{I}}•$

Abstract

Based on $(27.08\pm 0.14)\times 10^8$ $\ddot{I}ˆ(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the $\ddot{I}ˆ(3686)\to \hat{I}{\pounds }^{+}\bar{\hat{I}}{\pounds }^{-}\ddot{I}‰$ and $\hat{I}{\pounds }^{+}\bar{\hat{I}}{\pounds }^{-}\ddot{I}•$ decays are observed for the first time with statistical significances of 13.8$\ddot{I}ƒ$ and 7.6$\ddot{I}ƒ$, respectively. The corresponding branching fractions are measured to be $\mathcal{B}(\ddot{I}ˆ(3686)\to \hat{I}{\pounds }^{+}\bar{\hat{I}}{\pounds }^{-}\ddot{I}‰)=(1.90\pm 0.18\pm 0.21)\times 10^{-5}$ and $\mathcal{B}(\ddot{I}ˆ(3686)\to \hat{I}{\pounds }^{+}\bar{\hat{I}}{\pounds }^{-}\ddot{I}•)=(2.96\pm 0.54\pm 0.41)\times 10^{-6}$, where the first uncertainties are statistical and the second systematic.

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