U(1)${}_A$ Models of Fermion Masses Without a $\mu$ Problem

Abstract

We discuss the connection between models of fermion masses and mixing involving a string-motivated flavor/generation U(1)${}_A$ gauge symmetry and the $\mu$ term. We point out that in a certain class of such models the flavor physics can provide an appealing solution to the $\mu$ problem, naturally yielding a $\mu \sim O(m_{{}_W})$. A simple relationship between the $U(1{)}_A$ charge $q_H$ of the $\mu$-term and the average generational $U(1{)}_A$ charges of the down quark and leptonic sectors is derived. Finally, we construct an explicit model illustrating our results.

Comments: 12 pages, Latex File