Could an axion-like particle be hidden in $\eta_c\to\gamma\gamma$?

TL;DR

This paper explores whether an axion-like particle could be hidden within the observed decay of eta_c to two photons, analyzing current data and proposing further channels for confirmation.

Contribution

It introduces a method to extract axion-like particle parameters from eta_c decay data and discusses additional experimental channels for verification.

Findings

Axion-like particle parameters are compatible with current eta_c decay data.

Several channels are proposed for future experimental confirmation or exclusion.

Current data cannot exclude the presence of an axion-like particle in eta_c decay.

Abstract

We discuss the possibility of an axion-like particle being merged in the recent observation of $\eta_c \to \gamma\gamma$ at BESIII and find that it cannot be excluded in the current experimental data. The mass, width, and coupling strengths of the axion-like particle are extracted, and several other channels to confirm or exclude the existence of such an axion-like particle are also discussed.