First measurements of J/Psi decays into $\Sigma^+ \bar{\Sigma}^-$ and $\Xi^0 \bar{\Xi}^0$

TL;DR

This paper reports the first observation and measurement of the branching fractions for J/Psi decays into baryon-antibaryon pairs involving Sigma+ and Xi0 particles, based on a large dataset from the BESII detector.

Contribution

It provides the first measurements of J/Psi decays into Sigma+ Sigma- and Xi0 Xi0bar, expanding understanding of baryonic decay channels of J/Psi.

Findings

Branching fraction for J/Psi to Sigma+ Sigma- is (1.50 ± 0.10 ± 0.22)×10^{-3}.

Branching fraction for J/Psi to Xi0 Xi0bar is (1.20 ± 0.12 ± 0.21)×10^{-3}.

First observation of these decay modes.

Abstract

Based on 58 million J/Psi events collected with the BESII detector at the BEPC, the baryon pair processes J/Psi to $\Sigma^+ \bar{\Sigma}^-$ and J/Psi to $\Xi^0 \bar{\Xi}^0$ are observed for the first time. The branching fractions are measured to be ${\cal B}(J/Psi to \Sigma^+ \bar{\Sigma}^-)=(1.50\pm 0.10\pm 0.22)\times 10^{-3}$ and ${\cal B}(J/Psi to \Xi^0 \bar{\Xi}^0)=(1.20\pm 0.12\pm 0.21)\times 10^{-3}$, where the first errors are statistical and the second ones are systematic.