Exploratory studies for the position-space approach to hadronic light-by-light scattering in the muon $g-2$

TL;DR

This paper explores a position-space approach to better understand the hadronic light-by-light scattering contribution to the muon g-2, aiming to reduce theoretical uncertainties in light of upcoming experiments.

Contribution

It presents exploratory studies of the pion-pole contribution and fermion loop in a simple model, informing future full QCD computations of HLbL in muon g-2.

Findings

Insights into the pion-pole contribution in a simple model

Analysis of fermion loop without gluon exchanges in continuum

Preliminary data supporting future full QCD calculations

Abstract

The well-known discrepancy in the muon $g-2$ between experiment and theory demands further theory investigations in view of the upcoming new experiments. One of the leading uncertainties lies in the hadronic light-by-light scattering contribution (HLbL), that we address with our position-space approach. We focus on exploratory studies of the pion-pole contribution in a simple model and the fermion loop without gluon exchanges in the continuum and in infinite volume. These studies provide us with useful information for our planned computation of HLbL in the muon $g-2$ using full QCD.