The branching fraction measurements of $J/\ddot{I}ˆ$ decay into $\ddot{I}\hat{I}\cdot$ and $\ddot{I}•\hat{I}\cdot$ final states

Abstract

We present measurements of the branching fractions for the $J/\ddot{I}ˆ$ meson decays into the $\ddot{I}\hat{I}\cdot$ and $\ddot{I}•\hat{I}\cdot$ final states, based on data collected with the KEDR detector at the VEPP-4M collider. The data set consisted of 4.93 million $J/\ddot{I}ˆ$ events. The resulting branching fractions are: - $\mathcal{B}(J/\ddot{I}ˆ\to \ddot{I}\hat{I}\cdot )=(2.04\pm 0.58\pm 0.39)\times 10^{-4}$, - $\mathcal{B}(J/\ddot{I}ˆ\to \ddot{I}•\hat{I}\cdot )=(7.82\pm 1.17\pm 0.58)\times 10^{-4}$, where the first uncertainty is statistical and the second one is systematic. In the study of the $\ddot{I}\hat{I}\cdot$ decay, the dynamics of $J/\ddot{I}ˆ\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}\cdot$ is analyzed. The hints from contributions of $\ddot{I}(1450)\hat{I}\cdot$ and $a_2^{\pm }\ddot{I}{€}^{\mp }$ intermediate states are observed. Additional measured branching fractions in the model that includes $\ddot{I}(1450)\hat{I}\cdot$ and $a_2^{\pm }\ddot{I}{€}^{\mp }$ are: - $\mathcal{B}(J/\ddot{I}ˆ\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}\cdot )=(4.73\pm 0.49\pm 1.17)\times 10^{-4}$, - $\mathcal{B}(J/\ddot{I}ˆ\to (a_2^{+}\ddot{I}{€}^{-}+a_2^{-}\ddot{I}{€}^{+}))=(1.05\pm 0.37\pm 0.34)\times 10^{-3}$, - $\mathcal{B}(J/\ddot{I}ˆ\to \ddot{I}(1450)\hat{I}\cdot \to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}\cdot )<1.51\times 10^{-4}$, at a confidence level of 90\%. All results are consistent with previous studies.

Estimation of additional systematic uncertainties have been added. Interferences with the non-resonant processes are taken into account