A lattice calculation of the hadronic vacuum polarization contribution to (g – 2)_µ

¹ CP3-Origins, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
² Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J1P3
³ PRISMA Cluster of Excellence and Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
⁴ School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
⁵ Inst. de Física Teórica UAM/CSIC and Dpto de Física Teórica, U. Autónoma de Madrid, E-28049 Madrid
⁶ ETH Zürich, Institute for Theoretical Physics, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
⁷ Helmholtz Institute Mainz, University of Mainz, D-55099 Mainz, Germany

^* Speaker, e-mail: hartmut.wittig@uni-mainz.de

Published online: 26 March 2018

Abstract

We present results of calculations of the hadronic vacuum polarisation contribution to the muon anomalous magnetic moment. Specifically, we focus on controlling the infrared regime of the vacuum polarisation function. Our results are corrected for finite-size effects by combining the Gounaris-Sakurai parameterisation of the timelike pion form factor with the Lüscher formalism. The impact of quark-disconnected diagrams and the precision of the scale determination is discussed and included in our final result in two-flavour QCD, which carries an overall uncertainty of 6%. We present preliminary results computed on ensembles with N_f = 2 + 1 dynamical flavours and discuss how the long-distance contribution can be accurately constrained by a dedicated spectrum calculation in the iso-vector channel.