Feynman diagrams

Abstract

Precision measurements of electromagnetic couplings are fundamental tests of quantum electrodynamics (QED) and powerful probes of new physics beyond the Standard Model (BSM). The electron anomalous magnetic moment ae = 1 2 (ge 2) is among the most precisely measured observables in nature [1, 2]. The muon counterpart aμ is measured to 1 part in 107 [3] and reports a longstanding 3 4 deviation from the SM prediction, which may be a harbinger of new physics.