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

Recent results of two interesting classes of supersymmetric two-loop contributions to (g − 2)μ are presented. Two-loop diagrams involving a closed sfermion loop can amount to 5 × 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 γ5 and the ǫ-tensor.