Electromagnetic axial anomaly in a generalized linear sigma model

TL;DR

This paper develops an electromagnetic anomaly term within a generalized linear sigma model featuring two chiral nonets, and calculates two-photon decay rates of six pseudoscalar mesons, aligning well with experimental data.

Contribution

It introduces a new effective electromagnetic anomaly term for a generalized linear sigma model with two chiral nonets, including quark-antiquark and four-quark structures.

Findings

Calculated decay widths of six pseudoscalars into two photons.

Results show good agreement with experimental measurements.

Provides a theoretical framework for meson decay processes.

Abstract

We construct the electromagnetic anomaly effective term for a generalized linear sigma model with two chiral nonets, one with a quark-antiquark structure, the other one with a four quark content. We compute in the leading order of this framework the decays into two photons of six pseudoscalars: $\pi_0(137)$, $\pi_0(1300)$, $\eta(547)$, $\eta(958)$, $\eta(1295)$ and $\eta(1760)$. Our results agree well with the available experimental data.