Variations on Photon Vacuum Polarization

I provide updates for the theoretical predictions of the muon and electron anomalous magnetic moments, for the shift in the fine structure constant α(MZ )and for the weak mixing parameter $ \mathop {\sin }\nolimits^2 \mathop \Theta \nolimits_w (\mathop M\nolimits_Z ) $. Phenomenological results for Euclidean time correlators, the key objects in the lattice QCD approach to hadronic vacuum polarization, are briefly considered. Furthermore,I present a list of isospin breaking and electromagnetic corrections for the lepton moments, which may be used to supplement lattice QCD results obtained in the isospin limit and without the e.m. corrections.

Muon g – 2 theory: The hadronic part

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 [see formula in PDF] based on e+e- data [incl. τ data], [see formula in PDF] (NLO) and [see formula in PDF] (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 [see formula in PDF]. With these updates I find [see formula in PDF] a 4.1 σ deviation. Recent lattice QCD results and future prospects to improve hadronic contributions are discussed.