Hara's theorem, quark model, and gamma_5-dependent renormalization constants

Abstract

We discuss the applicability of gamma_5-dependent field renormalization as a means of renormalizing away the apparent violation of Hara's theorem observed in the quark model. It is pointed out that a result totally analogous to the violation of Hara's theorem is predicted by the quark model also for neutral baryons. For neutral baryons, however, such a result cannot be renormalized away. This proves that gamma_5-dependent renormalization does not provide a proper way for a hadron-level understanding of the violation of Hara's theorem observed in the quark model.