Observation of $\ddot{I}{‡}_{cJ}\to \hat{I}›\bar{\hat{I}}›\hat{I}\cdot$

Abstract

By analyzing $(448.1\pm 2.9)\times 10^6$ $\ddot{I}ˆ(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays of $\ddot{I}{‡}_{cJ}\to \hat{I}›\bar{\hat{I}}›\hat{I}\cdot$ ($J=0$, 1 and 2) are observed for the first time with statistical significances of $13.9\ddot{I}ƒ$, $6.7\ddot{I}ƒ$, and $8.2\ddot{I}ƒ$, respectively. The product branching fractions of $\ddot{I}ˆ(3686)\to {\hat{I}}^3\ddot{I}{‡}_{cJ}$ and $\ddot{I}{‡}_{cJ}\to \hat{I}›\bar{\hat{I}}›\hat{I}\cdot$ are measured. Dividing by the world averages of the branching fractions of $\ddot{I}ˆ(3686)\to {\hat{I}}^3\ddot{I}{‡}_{cJ}$, the branching fractions of $\ddot{I}{‡}_{cJ}\to \hat{I}›\bar{\hat{I}}›\hat{I}\cdot$ decays are determined to be $(2.31\pm 0.30\pm 0.21)\times 10^{-4}$, $(5.86\pm 1.38\pm 0.68)\times 10^{-5}$, and $(1.05\pm 0.21\pm 0.15)\times 10^{-4}$ for $J=0$, 1 and 2, respectively, where the first uncertainties are statistical and the second systematic.

9 pages, 4 figures