A Model for Fermion Mass Hierarchies and Mixings

Abstract

We present a model which contains three Abelian symmetries beyond the standard model. One is anomalous {\it à la} Green-Schwarz, and family-independent; the other two are family symmetries. All are broken at a large scale by stringy effects. The model is predictive in the neutrino sector: large mixing between ${\nu }_{\mu }-{\nu }_{\tau }$, and {\cal O}$({\lambda }^3)$ ${\nu }_e-{\nu }_{\mu }$ mixings. Its natural cut-off is the gauge unification scale, orders of magnitude below the perturbative string cut-off.

Comments: 11 pages, uses sprocl.sty