Determination of the relative phase in \psi' and J/\psi\ decays into baryon and antibaryon

TL;DR

This paper analyzes the decay processes of psi' and J/psi into baryon-antibaryon pairs, determining the phase difference between strong and electromagnetic interactions, and predicts related decay rates.

Contribution

It provides the first comprehensive fit considering experimental effects to determine the relative phase in these decays and offers predictions for branching fractions and production rates.

Findings

Large relative phase between strong and electromagnetic amplitudes

Accurate fits including energy spread and initial state radiation

Predicted branching fractions and continuum production rates

Abstract

With the recent measurements of psi' and J/psi decay into octet-baryon pairs, we study the relative phase between the strong and the electromagnetic amplitudes, and find a large phase by fitting the present data. The fits take into account the details of experimental effects, including energy spread and initial state radiation. We also predict some branching fractions of psi' decays and the continuum production rates at the J/psi mass based on the relative phase and absolute amplitudes obtained from the fits.