Twisted superspace: Non-renormalization and fermionic symmetries in certain heterotic-string-inspired non-supersymmetric field theories

Inspired by the tachyon-free nonsupersymmetric heterotic SO(16) x SO(16) string we consider a special class of nonsupersymmetric field theories: those that can be obtained from supersymmetric field theories by supersymmetry-breaking twists. We argue that such theories, like their supersymmetric counterparts, may still possess some fermionic symmetries as leftovers of the supergauge transformations and have special one-loop nonrenormalization properties due to holomorphicity. In addition, we extend the supergraph techniques to these theories to calculate some explicit supersymmetry-breaking corrections.