A model to explain angular distributions of $J/\psi$ and $\psi (2S)$ decays into $\Lambda \overline{\Lambda }$ and ${\Sigma }^0{\overline{\Sigma }}^0$

Abstract

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

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