Measurements of psi(2S) decays to octet baryon-antibaryon pairs

TL;DR

This study measures the decay rates of psi(2S) into various octet baryon-antibaryon pairs using BESII data, providing precise branching ratios and angular distribution parameters to enhance understanding of charmonium decays.

Contribution

The paper presents the first precise measurements of psi(2S) decays into octet baryon-antibaryon pairs, including branching ratios and angular distribution, using a large data sample from BESII.

Findings

Branching ratios for psi(2S) decays to p p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are quantified.

The angular distribution parameter alpha for psi(2S)->p p-bar is measured to be 0.82.

Results improve understanding of charmonium decay mechanisms.

Abstract

With a sample of 14 million psi(2S) events collected by the BESII detector at the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4, (3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.40+-0.32)*10E-4, respectively. In the decay psi(2S)->p p-bar, the angular distribution parameter alpha is determined to be 0.82+-0.17+-0.04.