Muon g – 2 theory: The hadronic part

¹ Deutsches Elektronen–Synchrotron (DESY), Platanenallee 6, D-15738 Zeuthen, Germany
² Humboldt–Universität zu Berlin, Institut für Physik, Newtonstrasse 15, D-12489 Berlin, Germany

^* e-mail: fjeger@physik.hu-berlin.de

Published online: 5 January 2018

Abstract

I present a status report of the hadronic vacuum polarization effects for the muon g–2, to be considered as an update of [1]. The update concerns recent new inclusive R measurements from KEDR in the energy range 1.84 to 3.72 GeV. For the leading order contributions I find based on e⁺e^- data [incl. τ data], (NLO) and (NNLO). Collecting recent progress in the hadronic light-by-light scattering I adopt π⁰, η, η' [95 ± 12] + axial-vector [8 ± 3] + scalar [-6 ± 1] + π, K loops [-20 ± 5] + quark loops [22 ± 4] + tensor [1 ± 0] + NLO [3 ± 2] which yields . With these updates I find a 4.1 σ deviation. Recent lattice QCD results and future prospects to improve hadronic contributions are discussed.