R-SYMMETRY BREAKING VERSUS SUPERSYMMETRY BREAKING

We point out a connection between R-symmetry and supersymmetry breakin g. We show that the existence of an R-symmetry is a necessary conditio n for supersymmetry breaking and a spontaneously broken R-symmetry is a sufficient condition provided two conditions are satisfied. These co nditions are: genericity, i.e. the effective lagrangian is a generic l agrangian consistent with the symmetries of the theory (no fine tuning ), and calculability, i.e. the low-energy theory can be described by a supersymmetric Wess-Zumino effective lagrangian without gauge fields. All known models of dynamical supersymmetry breaking possess such a s pontaneously broken R-symmetry and therefore contain a potentially tro ublesome axion. However, we use the fact that genericity is not a feat ure of supersymmetric theories, even when non-perturbative renormaliza tion is included, to show that the R-symmetry can in many cases be exp licitly broken without restoring supersymmetry and so the axion can be given an acceptably large mass.