Meson PVV Interactions are determined by Quark Loops

TL;DR

This paper demonstrates that abnormal parity three-body meson interactions, including radiative decays involving pseudoscalars, can be effectively described by quark loops at zero momentum, with minimal parameters, aligning well with experimental data.

Contribution

It introduces a quark loop model at zero external momentum to describe meson interactions, emphasizing the role of $U(N_f)$ symmetry and minimal parameters.

Findings

Good agreement with experimental decay rates

Few parameters needed for accurate modeling

Applicable to three-body decays with pion pairs

Abstract

We show that all abnormal parity three-body meson interactions can be adequately described by quark loops, evaluated at zero external momentum, with couplings determined by $U(N_f)$ symmetry. We focus primarily on radiative meson decays which involve one pseudoscalar. The agreement with experiment for non-rare decays is surprisingly good and requires very few parameters, namely the coupling constants $g_{\pi qq}$ and $g_{\rho qq}$ and some mixing angles. This agreement extends to some three-body decays that are dominated by pion pairs in a P-wave state.