Improved measurements of $\chi_{cJ} \rightarrow \Sigma^+ \bar{\Sigma}^-$ and $\Sigma^0 \bar{\Sigma}^0$ decays

TL;DR

This paper reports the first observation of certain $ ext{chi}_{cJ}$ decays into $ ext{Sigma}$ hyperon pairs and provides improved measurements of their branching fractions, confirming isospin symmetry predictions.

Contribution

First observation of $ ext{chi}_{c1,2}$ decays into $ ext{Sigma}$ pairs and improved measurements of $ ext{chi}_{c0}$ decay branching fractions.

Findings

First observation of $ ext{chi}_{c1,2}$ decays to $ ext{Sigma}$ pairs.

Measured branching fractions with improved precision.

Branching fraction ratios align with isospin symmetry predictions.

Abstract

Using a data sample of $(448.1\pm2.9)\times 10^6~\psi(3686)$ events collected with the BESIII detector at the BEPCII collider, we present measurements of branching fractions for the decays $\chi_{cJ} \rightarrow \Sigma^+ \bar{\Sigma}^-$ and $\Sigma^0 \bar{\Sigma}^0$. The decays $\chi_{c1,2}\rightarrow \Sigma^+ \bar{\Sigma}^-$ and $\Sigma^0 \bar{\Sigma}^0$ are observed for the first time, and the branching fractions for $\chi_{c0}\rightarrow \Sigma^+ \bar{\Sigma}^-$ and $\Sigma^0 \bar{\Sigma}^0$ decays are measured with improved precision. The branching fraction ratios between the charged and neutral modes are consistent with the prediction of isospin symmetry.