NATURALNESS VERSUS SUPERSYMMETRIC NON-RENORMALIZATION THEOREMS

We give an intuitive proof of a new non-renormalization theorem in sup ersymmetric field theories. It applies both perturbatively and non-per turbatively. The superpotential is not renormalized in perturbation th eory but receives non-perturbative corrections. However, these non-per turbative corrections are not generic functions of the fields consiste nt with the symmetries. Certain invariant terms are not generated. Thi s violation of naturalness has applications to dynamical supersymmetry breaking.