Electromagnetic axial anomaly in a generalized linear sigma model

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.

Comments: 15 pages; version to be published in Phys. Rev. D