Effects of an extra U(1) axial condensate on the strong decays of pseudoscalar mesons

TL;DR

This paper investigates how a persistent U(1)-breaking condensate affects the strong decay processes of light and exotic pseudoscalar mesons within an effective Lagrangian framework, extending previous studies on radiative decays.

Contribution

It introduces a model incorporating a U(1) axial condensate's effects on meson decays, including new predictions for the decay patterns of eta, eta', and an exotic eta_X state.

Findings

The U(1) condensate influences decay widths and channels of pseudoscalar mesons.

Predictions for decay rates of eta, eta', and eta_X states are provided.

The model extends understanding of chiral symmetry breaking effects on meson phenomenology.

Abstract

We consider a scenario (supported by some lattice results) in which a U(1)-breaking condensate survives across the chiral transition in QCD. This scenario has important consequences for the pseudoscalar-meson sector, which can be studied using an effective Lagrangian model. In particular, generalizing the results obtained in two previous papers, where the effects on the radiative decays eta,eta' --> gamma gamma were studied, in this paper we study the effects of the U(1) chiral condensate on the strong decays of the "light" pseudoscalar mesons, i.e., eta,eta' --> 3pi^0; eta,eta' --> pi^+ pi^- pi^0; eta' --> eta pi^0 pi^0; eta' --> eta pi^+ pi^-; and also on the strong decays of an exotic ("heavy") SU(3)-singlet pseudoscalar state eta_X, predicted by the model.