The light-by-light contribution to the muon anomalous magnetic moment from the axial-vector mesons exchanges within the nonlocal quark model

TL;DR

This paper estimates the axial-vector mesons' contribution to the muon anomalous magnetic moment via light-by-light scattering within a nonlocal quark model, providing a refined calculation of this specific quantum effect.

Contribution

It introduces a nonlocal quark model with re-fitted parameters to evaluate axial-vector meson contributions to muon g-2, including pi-a_1 mixing effects.

Findings

Estimated a_1+f_1 mesons' contribution: (3.6±1.8)×10^{-11}

Model accounts for mixing effects in axial-vector sector

Provides a refined theoretical estimate for muon g-2

Abstract

The contribution of axial-vector mesons to the muon's anomalous magnetic moment through a light-by-light process is considered within a nonlocal quark model. The model is based on a four-quark interaction with scalar--pseudoscalar and vector--axial-vector sectors. While the transverse component of the axial-vector corresponds to a spin-1 particle, the unphysical longitudinal component is mixed with a pseudoscalar meson. The model parameters are re-fitted to the pion properties in the presence of pi-a_1 mixing. The obtained estimation for the light-by-light contribution of a_1+f_1 mesons is (3.6+-1.8)*10^{-11}.