Hadronic light-by-light scattering in the muon g-2: impact of proposed measurements of the (pi^0 -> gamma gamma) decay width and the (gamma^* gamma -> pi^0) transition form factor with the KLOE-2 experiment

TL;DR

This paper explores how upcoming measurements at KLOE-2 of the pion decay width and transition form factor can refine estimates of the pion-exchange contribution to the muon g-2's hadronic light-by-light scattering, highlighting modeling limitations.

Contribution

It assesses the potential impact of KLOE-2 measurements on reducing uncertainties in the pion-exchange contribution to muon g-2 and discusses associated modeling challenges.

Findings

KLOE-2 measurements can significantly improve the precision of the pion-exchange contribution.

Modeling the off-shellness of the pion remains a key limitation.

Enhanced data may reduce theoretical uncertainties in muon g-2 calculations.

Abstract

We discuss, how planned measurements at KLOE-2 of the (pi^0 -> gamma gamma) decay width and the (gamma^* gamma -> pi^0) transition form factor can improve estimates for the numerically dominant pion-exchange contribution to hadronic light-by-light scattering in the muon g-2 and what are the limitations related to the modelling of the off-shellness of the pion.