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

TL;DR

This paper analyzes baryon-antibaryon pair production from $ ext{psi}$ decays using partial wave analysis, estimating very small effective radii around 0.04 fm, and suggests these decays are ideal for searching excited baryon resonances.

Contribution

It introduces a method to determine the effective radius in $ ext{psi}$ decays and applies it to recent BESIII data, revealing very small radii and proposing new approaches for other reactions.

Findings

Effective radii are approximately 0.04 fm.

Decays are suitable for searching low-spin excited baryons.

Proposes methods to determine effective radius in other reactions.

Abstract

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 $J/\psi\to \Lambda\bar{\Lambda}$ 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.