FeynArts model file for MSSM transition counterterms from DREG to DRED

Abstract

The FeynArts model file MSSMdreg2dred.mod implements MSSM transition counterterms which can convert one-loop Green functions from dimensional regularization to dimensional reduction. They correspond to a slight extension of the well-known Martin/Vaughn counterterms, specialized to the MSSM, and can serve also as supersymmetry-restoring counterterms. The paper provides full analytic results for the counterterms and gives one- and two-loop usage examples. The model file can simplify combining MSbar-parton distribution functions with supersymmetric renormalization or avoiding the renormalization of epsilon-scalars in dimensional reduction.