The Theoretical Prediction for the Muon Anomalous Magnetic Moment

▪ Abstract This article reviews the standard-model prediction for the anomalous magnetic moment of the muon and describes recent updates of QED, electroweak, and hadronic contributions. Comparison of theory and experiment suggests a 2.4 σ difference if [Formula: see text] hadrons data are used to evaluate the main hadronic effects, but a smaller discrepancy if hadronic τ decay data are employed. Implications of a deviation for “new physics” contributions, along with an outlook for future improvements in theory and experiment, are briefly discussed.