Anomalous Magnetic Moment of Lepton and Quantum Electrodynamics

Abstract

The anomalous magnetic moment, or g-2, of the electron was discovered in 1947 and was shown to be a quantum-field-theoretic effect in 1948. Since then, precision of both experiment and theory have been greatly improved. The relative uncertainty of electron g-2 is now about 10^<-9>. The muon g-2 was also measured precisely and reached the relative uncertainty of 10^<-6>. Comparing theory and experiment in such a high precision, we might be able to detect a hint of new physics beyond the Standard Model of elementary particles.