Observation of $\ddot{I}ˆ(3686)\to K^{-}\hat{I}›(1520)\bar{\hat{I}}{ž}^{+}+c.c.$

Abstract

Based on $(2712.4\pm 14.3)\times 10^6$ $\ddot{I}ˆ(3686)$ events collected at the BESIII detector operating at the BEPCII collider, we present the first observation of the decay $\ddot{I}ˆ(3686)\to K^{-}\hat{I}›(1520)\bar{\hat{I}}{ž}^{+}+c.c.$. The product branching fraction $\mathcal{B}[\ddot{I}ˆ(3686)\to K^{-}\hat{I}›(1520)\bar{\hat{I}}{ž}^{+}+c.c.]\times \mathcal{B}[\hat{I}›(1520)\to p{K}^{-}]$ is measured to be $(9.5\pm 0.8\pm 1.1)\times 10^{-7}$, where the first uncertainty is statistical and the second systematic.