Supersymmetric two-loop contributions to the anomalous magnetic moment of the muon

Abstract

Recent results of two interesting classes of supersymmetric two-loop contributions to (g-2)_mu are presented. Two-loop diagrams involving a closed sfermion loop can amount to 5*10^{-10} or almost one standard deviation of the current experimental uncertainty, and two-loop diagrams with a closed chargino/neutralino loop can be similarly large. The dependence of these two classes on the unknown supersymmetric parameters and the sensitivity on existing experimental constraints on the parameter space are quite different. We also comment on the calculational techniques, in particular the large mass expansion and the treatment of gamma_5 and the epsilon-tensor.