THE THEORETICAL PREDICTION FOR THE MUON ANOMALOUS MAGNETIC MOMENT

The Standard Model preciction for the muon anomalous magnetic moment is reviewed. Recent updates of QED, electroweak and hadronic contributions are described. Comparison of theory and experiment suggests a $2.4\sigma$ difference if $e^+e^- \rightarrow$ hadrons data are used to evaluate the main hadronic effects, but a smaller discrepancy if hadronic $\tau$ 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