Further study of the helicity selection rule evading mechanism in $\eta_c$, $\chi_{c0}$ and $h_c$ decaying to baryon anti-baryon pairs

TL;DR

This paper explores how long-distance hadron loop effects can bypass the helicity selection rule in certain charmonium decays to baryon-antibaryon pairs, challenging the expectation of suppression from perturbative QCD.

Contribution

It demonstrates that charmed hadron loops significantly contribute to these decays, providing evidence for the evading mechanism of the helicity selection rule in charmonium baryon decays.

Findings

Hadron loops play a crucial role in $ ext{eta}_c$, $ ext{chi}_{c0}$, and $h_c$ decays.

Long-distance effects can evade the helicity selection rule.

Supports the mechanism allowing these decays despite perturbative QCD suppression.

Abstract

We investigate the long distance contribution via charmed hadron loops in the processes $\eta_c$, $\chi_{c0}$ and $h_c$ decaying to baryon anti-baryon pairs, which are supposed to be highly suppressed by the helicity selection rule as a consequence of the perturbative QCD framework. With an effective Lagrangian method, our estimation result indicates that such hadron loops play an important role in these hadronic decays. It is a further test of the evading mechanism for the helicity selection rule in charmonium baryon-antibaryon decays.