A model to explain angular distributions of $J/\ddot{I}ˆ$ and $\ddot{I}ˆ(2S)$ decays into $\hat{I}›\overline{\hat{I}}›$ and $\hat{I}{\pounds }^0\overline{\hat{I}}{\pounds }^0$

Abstract

BESIII data show a particular angular distribution for the decay of the $J/\ddot{I}ˆ$ and $\ddot{I}ˆ(2S)$ mesons into the hyperons $\hat{I}›\overline{\hat{I}}›$ and $\hat{I}{\pounds }^0\overline{\hat{I}}{\pounds }^0$. More in details the angular distribution of the decay $\ddot{I}ˆ(2S)\to \hat{I}{\pounds }^0\overline{\hat{I}}{\pounds }^0$ exhibits an opposite trend with respect to that of the other three channels: $J/\ddot{I}ˆ\to \hat{I}›\overline{\hat{I}}›$, $J/\ddot{I}ˆ\to \hat{I}{\pounds }^0\overline{\hat{I}}{\pounds }^0$ and $\ddot{I}ˆ(2S)\to \hat{I}›\overline{\hat{I}}›$. We define a model to explain the origin of this phenomenon.

6 pages, 7 figures, to be published in Chinese Physics C