Study of the processes $\chi_{cJ} \to \Xi^- \bar{\Xi}^+$ and $\Xi^0 \bar{\Xi}^0$

TL;DR

This study measures the branching fractions and angular distributions of specific charmonium decays into Xi baryon pairs using a large data sample, observing some decays for the first time with high significance.

Contribution

It provides the first observation of $ ext{chi}_{c1,2} o ext{Xi}^0 ar{ ext{Xi}}^0$ decays and improves the precision of branching fraction measurements for these processes.

Findings

First observation of $ ext{chi}_{c1,2} o ext{Xi}^0 ar{ ext{Xi}}^0$ decays.

Measured branching fractions with improved accuracy.

Results consistent with previous measurements.

Abstract

Using $448.1\times 10 ^6$ $\psi(3686)$ decays collected with the BESIII detector at the BEPCII $e^+e^-$ storage rings, the branching fractions and angular distributions of the decays $\chi_{cJ}\to\Xi^-\bar{\Xi}^+$ and $\Xi^0\bar{\Xi}^0$ $(J = 0, 1, 2)$ are measured based on a partial-reconstruction technique. The decays $\chi_{c1}\to\Xi^0\bar{\Xi}^0$ and $\chi_{c2}\to\Xi^0\bar{\Xi}^0$ are observed for the first time with statistical significances of 7$\sigma$ and 15$\sigma$, respectively. The results of this analysis are in good agreement with previous measurements and have significantly improved precision.