The effective radius for production of baryon-antibaryon pairs from $psi$ decays

By using the covariant L-S Scheme for the partial wave analysis, we deduce the ratios between the S-wave and D-wave contributions from the recent data of $psi(1^-) to B_8(1/2^+) bar{B}_8(1/2^-)$ from the BESIII collaboration. For the $J/psito Lambdabar{Lambda}$ and $J/psi(psi(2S))to Sigma^{+}bar{Sigma}^{-}$, the ratios are fixed and the average angular momenta are computed to estimate the effective radii of these processes. The results show that the effective radii of these decays of $J/psi(psi(2S))$ are very small, which are around 0.04 fm. Thus, it is a nice place to search excited baryon resonances with lower spin in the decays of $J/psi(psi(2S))$. Furthermore, for the other $psi(1^-) to B_8(1/2^+) bar{B}_8(1/2^-)$ reactions, we propose some methods to get such effective radius.