Short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude: an update

Abstract We reassess the impact of short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude on the anomalous magnetic moment of the muon, $$a_\mu =(g-2)_\mu /2$$ a μ = ( g - 2 ) μ / 2 , by comparing different solutions that have recently appeared in the lite...

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Bibliographic Details
Main Authors: G. Colangelo, F. Hagelstein, M. Hoferichter, L. Laub, P. Stoffer
Format: Article
Language:English
Published: SpringerOpen 2021-08-01
Series:European Physical Journal C: Particles and Fields
Online Access:https://doi.org/10.1140/epjc/s10052-021-09513-x
Description
Summary:Abstract We reassess the impact of short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude on the anomalous magnetic moment of the muon, $$a_\mu =(g-2)_\mu /2$$ a μ = ( g - 2 ) μ / 2 , by comparing different solutions that have recently appeared in the literature. In particular, we analyze the relevance of the exact axial anomaly and its impact on $$a_\mu $$ a μ and conclude that it remains rather limited. We show that all recently proposed solutions agree well within uncertainties on the numerical estimate of the impact of short-distance constraints on $$a_\mu $$ a μ , despite differences in the concrete implementation. We also take into account the recently calculated perturbative corrections to the massless quark loop to update our estimate and outline the path towards future improvements.
ISSN:1434-6044
1434-6052