One PI and Wilsonian Actions in SUSY theories

Abstract: The soft breaking terms in supersymmetric theories are calculated at some high scale characterizing the hidden supersymmetry breaking sector, and then evolved down to the TeV scale. These parameters are usually presented as the ones that should be compared to experiment. The physical parameters however are those occurring in the quantum effective (1PI) action - in particular the physical mass is the location of the pole in the full quantum propagator. Here we discuss the relation between the two and the possible existence of additive contributions to the gaugino mass. We argue that infra red effects which violate non-renormalization theorems are absent (for the 1PI action) if the calculation is done at a generic point in field space so that an effective IR cutoff is present. It follows that if a gaugino mass term is absent in the Wilsonian action it is absent in the 1PI action.