Hidden gauge formalism for the radiative decays of axial-vector mesons

TL;DR

This paper uses the hidden gauge symmetry formalism to analyze the radiative decays of axial-vector mesons into pseudoscalar mesons and photons, ensuring gauge invariance and comparing results with previous approaches.

Contribution

It applies the hidden gauge symmetry formalism to study axial-vector meson radiative decays, explicitly demonstrating gauge invariance and including anomalous loop contributions.

Findings

Calculated decay widths for a1(1260) and b1(1235) into pi gamma.

Confirmed gauge invariance of the decay amplitude set.

Compared results with previous formalisms, showing consistency or differences.

Abstract

The radiative decay of the axial-vector resonances into a pseudoscalar meson and a photon is studied using the vector meson Lagrangian obtained from the hidden gauge symmetry (HGS) formalism. The formalism is well suited to study this problem since it deals with pseudoscalar and vector mesons in a unified way, respecting chiral invariance. We show explicitly the gauge invariance of the set of diagrams that appear in the approach and evaluate the radiative decay width of the a1(1260) and b1(1235) axial vector meson resonances into pi gamma. We also include the contribution of loops involving anomalous couplings and compare the results to those obtained previously within another formalism.