New Tools for Fermion Masses from Extra Dimensions

Abstract

We present models in which the observed fermion masses and mixings are generated by dynamically localizing the three generations of matter in a flat compact extra dimension. We first construct models assuming the hierarchy problem is addressed by the existence of large extra dimensions, i.e. the fundamental scale is not far above a TeV and supersymmetry is not imposed. These models are compactified, chiral, and don't require fine-tuning to generate the top mass. Limits on the compactification scale based on flavor-changing neutral currents are relaxed compared to those on existing models. We then supersymmetrize some of these models. Using N=1 superspace language in extra dimensions, we find space-dependent flat directions which can be used to localize fields. Finally, we discuss methods of breaking supersymmetry and the impact of these models on the superpartner spectrum.