Observation of $\eta_{c}$ decay into $\Sigma^{+}\bar{\Sigma}^{-}$ and $\Xi^{-}\bar{\Xi}^{+}$ final states

TL;DR

This paper reports the first observation of specific decay modes of the $ extit{ extbf{eta}}_{c}$ meson into baryon-antibaryon pairs, measuring their branching fractions using BESIII data, which informs understanding of decay rules in charmonium physics.

Contribution

It presents the first measurement of $ extit{ extbf{eta}}_{c}$ decays into $ extbf{ extit{ extSigma}}^{+}ar{ extbf{ extSigma}}^{-}$ and $ extbf{ extXi}}^{-}ar{ extbf{ extXi}}^{+}$, providing new experimental data on charmonium decay processes.

Findings

Branching fraction for $ extit{ extbf{eta}}_{c} o extbf{ extSigma}}^{+}ar{ extbf{ extSigma}}^{-}$ is approximately 2.11×10^{-3}.

Branching fraction for $ extit{ extbf{eta}}_{c} o extbf{ extXi}}^{-}ar{ extbf{ extXi}}^{+}$ is approximately 0.89×10^{-3}.

Results offer insights into the helicity selection rule in charmonium decays.

Abstract

Using a data sample of $2.25\times10^{8}$ $J/\psi$ events collected with the BESIII detector, we present the first observation of the decays of $\eta_{c}$ mesons to $\Sigma^{+}\bar{\Sigma}^{-}$ and $\Xi^{-}\bar{\Xi}^{+}$. The branching fractions are measured to be $(2.11\pm0.28_{\rm stat.}\pm0.18_{\rm syst.}\pm0.50_{\rm PDG})\times10^{-3}$ and $(0.89\pm0.16_{\rm stat.}\pm0.08_{\rm syst.}\pm0.21_{\rm PDG})\times10^{-3}$ for $\eta_{c} \to \Sigma^{+}\bar{\Sigma}^{-}$ and $\Xi^{-}\bar{\Xi}^{+}$, respectively. These branching fractions provide important information on the helicity selection rule in charmonium-decay processes.