Study of $J/\ddot{I}ˆ$ and $\ddot{I}ˆ(3686)$ decay to $\hat{I}›\bar{\hat{I}}›$ and $\hat{I}{\pounds }^0\bar{\hat{I}}{\pounds }^0$ final states

Abstract

Using $1310.6\times 10^6$ $J/\ddot{I}ˆ$ and $447.9\times 10^6$ $\ddot{I}ˆ(3686)$ events collected with the BESIII detector at the BEPCII $e^{+}{e}^{-}$ collider, the branching fractions and the angular distributions of $J/\ddot{I}ˆ$ and $\ddot{I}ˆ(3686)$ decays to $\hat{I}›\bar{\hat{I}}›$ and $\hat{I}{\pounds }^0\bar{\hat{I}}{\pounds }^0$ final states are measured. The branching fractions are in agreement with, and much more precise than, the averages of previously published results. The polar angular distributions of $\ddot{I}ˆ(3686)$ decays are measured for the first time, while those of $J/\ddot{I}ˆ$ decays are measured with much improved precision. In addition, the ratios of branching fractions $\frac{\mathcal{B}(\ddot{I}ˆ(3686)\to \hat{I}›\bar{\hat{I}}›)}{\mathcal{B}(J/\ddot{I}ˆ\to \hat{I}›\bar{\hat{I}}›)}$ and $\frac{\mathcal{B}(\ddot{I}ˆ(3686)\to \hat{I}{\pounds }^0\bar{\hat{I}}{\pounds }^0)}{\mathcal{B}(J/\ddot{I}ˆ\to \hat{I}{\pounds }^0\bar{\hat{I}}{\pounds }^0)}$ are determined to test the "12\% rule".

10 pages, 8 figures