Search for new decay modes of the $\ddot{I}{ˆ}_2(3823)$ and the process $e^{+}{e}^{-}\to \ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{ˆ}_2(3823)$

Abstract

The decays $\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c0,1,2},\ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ,\ddot{I}{€}^0\ddot{I}{€}^{0}J/\ddot{I}ˆ,\hat{I}\cdot J/\ddot{I}ˆ$, and $\ddot{I}{€}^{0}J/\ddot{I}ˆ$ are searched for using the reaction $e^{+}{e}^{-}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\ddot{I}{ˆ}_2(3823)$ in a 19 fb${}^{-1}$ data sample collected at center-of-mass energies between 4.1 and 4.7 GeV with the BESIII detector. The process $\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c1}$ is observed in a 9 fb${}^{-1}$ data sample in the center-of-mass energy range 4.3 to 4.7 GeV, which confirms a previous observation but with a higher significance of $11.8\ddot{I}ƒ$, and evidence for $\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c2}$ is found with a significance of $3.2\ddot{I}ƒ$ for the first time. The branching-fraction ratio $\frac{\mathcal{B}(\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c2})}{\mathcal{B}(\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c1})}$ is determined. No significant $\ddot{I}{ˆ}_2(3823)$ signals are observed for any of the other decay channels. Upper limits of branching-fraction ratios for $\ddot{I}{ˆ}_2(3823)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ,\ddot{I}{€}^0\ddot{I}{€}^{0}J/\ddot{I}ˆ,\hat{I}\cdot J/\ddot{I}ˆ,\ddot{I}{€}^{0}J/\ddot{I}ˆ,{\hat{I}}^3\ddot{I}{‡}_{c0}$ relative to $\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c1}$ are reported. The process $e^{+}{e}^{-}\to \ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{ˆ}_2(3823)$ is also searched for, and we find evidence for the process with a significance of $4.3\ddot{I}ƒ$. The average cross-section ratio $\frac{\ddot{I}ƒ(e^{+}{e}^{-}\to \ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{ˆ}_2(3823))}{\ddot{I}ƒ(e^{+}{e}^{-}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\ddot{I}{ˆ}_2(3823))}$ is also determined.

8 pages, 4 figures