Chiral Symmetry and Charmonium Decays to Two Pseudoscalars

TL;DR

This paper uses hard pion Chiral Perturbation Theory to analyze charmonium decays into two pseudoscalar mesons, revealing the absence of leading chiral logarithms in certain decay channels of spin-zero and spin-two states.

Contribution

It demonstrates that leading chiral logarithms are absent in specific charmonium decays, providing new insights into chiral symmetry effects in these processes.

Findings

Leading chiral logarithm absent in $ ext{chi}_{c0}$ and $ ext{chi}_{c2}$ decays

Results applicable to all fully chiral singlet states of spin zero and two

Decays from $J/ ext{psi}$ and $ ext{psi}(nS)$ do not yield simple predictions

Abstract

We apply hard pion Chiral Perturbation Theory to charmonium decays to $\pi\pi$, $KK$ and $\eta\eta$. We first discuss why we expect to be able to provide results for the chiral logarithms in $\chi_{c0}$ and $\chi_{c2}$ decays to two pseudoscalars while for the decays from $J/\psi$, $\psi(nS)$ and $\chi_{c1}$ no simple prediction is possible. The leading chiral logarithm turns out to be absent for $\chi_{c0},\chi_{c2}\to PP$. This result is true for all fully chiral singlet states of spin zero and two.