Puzzles in the hadronic contributions to the muon anomalous magnetic moment

Abstract

Abstract We summarize recent developments in the Standard-Model evaluation of the anomalous magnetic moment of the muon aμ , both in the hadronic-light-by-light and hadronic-vacuum-polarization contributions. The current situation for the latter is puzzling as we are confronted with multiple discrepancies that are not yet understood. We present updated fits of a dispersive representation of the pion vector form factor to the new CMD-3 data set and quantify the tensions with the other high-statistics e + e - → π + π - experiments in the contribution to aμ in the energy range up to 1 GeV, as well as in the corresponding contribution to the intermediate Euclidean window. See ref. [1] for an extended version of this contribution.