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arXiv · 2110.05493

Chiral extrapolation of hadronic vacuum polarization

Gilberto Colangelo·Martin Hoferichter·Bastian Kubis·Malwin Niehus·Jacobo Ruiz de Elvira
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Abstract

We study the pion-mass dependence of the two-pion channel in the hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon $a_\mu^\text{HVP}$, by using an Omn\`es representation for the pion vector form factor with the phase shift derived from the inverse-amplitude method (IAM). Our results constrain the dominant isospin-$1$ part of the isospin-symmetric light-quark contribution, and should thus allow one to better control the chiral extrapolation of $a_\mu^\text{HVP}$, required for lattice-QCD calculations performed at larger-than-physical pion masses. In particular, the comparison of the one- and two-loop IAM allows us to estimate the associated systematic uncertainties and show that these are under good control.

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Gilberto Colangelo, Martin Hoferichter, Bastian Kubis, Malwin Niehus, Jacobo Ruiz de Elvira. 2021-10-11. Chiral extrapolation of hadronic vacuum polarization. https://doi.org/10.1016/j.physletb.2021.136852

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