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

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