Charged pions asymmetry from the decay of light neutral axial mesons due to interference

TL;DR

This paper models the decay processes of light neutral axial mesons using flavor U(3) quark interactions, analyzing interference effects that lead to charged pion asymmetry in decay rates.

Contribution

It introduces a theoretical framework for understanding charged pion asymmetry from neutral axial meson decays considering meson mixing and interference effects.

Findings

Decay rate ratio $rac{\Gamma_{\pi^+}}{\Gamma_{\pi^-}}$ is slightly less than one.

Interference effects from meson mixing influence decay asymmetries.

Absorption or inelastic processes can suppress charged pion production.

Abstract

Effective three meson couplings, based in flavor U(3) quark-antiquark interactions, are considered to describe two light neutral axial meson Strong decays, $A \sim f_1(1285)$ and $f_{1S} (1420)$, and the charged rho meson decay in the following channels: $A \to \rho^\mp (770)+ \pi^\pm$, $A\to a_0^\mp (980) +\pi^\pm$ and $\rho^\pm \to \pi^\pm \pi^0$. By considering neutral meson mixings, such as $f_1(1285) - a_1^0(1260)$, $f_{1S}(1420) - a_1^0(1260)$ and $\eta-\pi^0$ for the channels investigated, the leading three-meson interactions may lead to decay amplitudes that undergo interference and a resulting ratio of decay rate into charged pions, $\Gamma_{\pi^+}/\Gamma_{\pi^-}$, slightly smaller than one. For that it will be assumed that the produced charged vector mesons or charged scalar mesons undergo absorption, decay into channels without charged pions, or any other inelastic process that may suppress their decays into charged pions.