Electromagnetic corrections to the hadronic vacuum polarization of the photon within QEDL and QEDM

Andrea Bussone; Michele Della Morte; Tadeusz Janowski

doi:10.1051/epjconf/201817506005

Proceedings

Open Access

EPJ Web of Conferences 175, 06005 (2018)
https://doi.org/10.1051/epjconf/201817506005

Electromagnetic corrections to the hadronic vacuum polarization of the photon within QED_L and QED_M

Andrea Bussone^*, Michele Della Morte and Tadeusz Janowski

CP 3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark

^* Speaker, e-mail: bussone@cp3-origins.net

Published online: 26 March 2018

Abstract

We compute the leading QED corrections to the hadronic vacuum polarization (HVP) of the photon, relevant for the determination of leptonic anomalous magnetic moments, a_l. We work in the electroquenched approximation and use dynamical QCD configurations generated by the CLS initiative with two degenerate flavors of nonperturbatively O(a)-improved Wilson fermions. We consider QED_L and QED_M to deal with the finite-volume zero modes. We compare results for the Wilson loops with exact analytical determinations. In addition we make sure that the volumes and photon masses used in QED_M are such that the correct dispersion relation is reproduced by the energy levels extracted from the charged pions two-point functions. Finally we compare results for pion masses and the HVP between QED_L and QED_M. For the vacuum polarization, corrections with respect to the pure QCD case, at fixed pion masses, turn out to be at the percent level.

© The Authors, published by EDP Sciences, 2018

This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (http://creativecommons.org/licenses/by/4.0/).