Ballpark prediction for the hadronic light-by-light contribution to the muon (g-2)_{\mu}

TL;DR

This paper provides an estimate of the hadronic light-by-light scattering contribution to the muon g-2 using a quark loop model informed by the pion exchange contribution, updating previous calculations with a focus on the pseudoscalar transition form factor.

Contribution

It introduces a method to estimate the hadronic light-by-light contribution based on the momentum dependence of the dressed quark mass and pion exchange, offering an updated calculation of the bc^0b contribution.

Findings

Updated estimate of the bc^0b contribution to muon g-2

Emphasizes the importance of the pseudoscalar transition form factor

Provides a framework for incorporating momentum dependence in calculations

Abstract

Using the momentum dependence of the dressed quark mass and the well-known formulae for the mass dependent quark-loop contribution to the light-by-light scattering insertions, we compute the hadronic light-by-light contribution to the muon anomalous magnetic moment. The relevant momentum running in the quark loop is calculated from the $\pi^0$ exchange contribution to the light- by-light scattering. Special emphasis on the reconstruction of the pseudoscalar transition form factor is made, and the $\pi^0$ contribution to the hadronic light-by-light is, as well, updated.