Observation of $\ddot{I}{‡}_{cJ}(J=0,1,2)\to p\bar{p}\hat{I}\cdot \hat{I}\cdot$

Abstract

Using $(2712.4\pm 14.3)\times 10^6$ $\ddot{I}ˆ(3686)$ events collected by the BESIII detector operating at the BEPCII storage ring, the decays $\ddot{I}{‡}_{cJ}(J=0,1,2)\to p\bar{p}\hat{I}\cdot \hat{I}\cdot$ are observed for the first time through the radiative transition $\ddot{I}ˆ(3686)\to {\hat{I}}^3\ddot{I}{‡}_{cJ}$. The statistical significances for $\ddot{I}{‡}_{cJ}$ signals are all larger than 5$\ddot{I}ƒ$. The branching fractions of $\ddot{I}{‡}_{c0,1,2}\to p\bar{p}\hat{I}\cdot \hat{I}\cdot$ are determined to be $(5.75\pm 0.59\pm 0.42)\times 10^{-5}$, $(1.40\pm 0.33\pm 0.17)\times 10^{-5}$, and $(2.64\pm 0.40\pm 0.27)\times 10^{-5}$, respectively, where the first uncertainties are statistical and the second systematic. No evident resonant structures are found in the $p\bar{p}$ and $p\hat{I}\cdot /\bar{p}\hat{I}\cdot$ systems.

17 pages, 16 figures