New Tools for Fermion Masses from Extra Dimensions

We present models in which the observed fermion masses and mixings aregenerated by dynamically localizing the three generations of matter in a flatcompact extra dimension. We first construct models assuming the hierarchyproblem is addressed by the existence of large extra dimensions, i.e. thefundamental scale is not far above a TeV and supersymmetry is not imposed.These models are compactified, chiral, and don't require fine-tuning togenerate the top mass. Limits on the compactification scale based onflavor-changing neutral currents are relaxed compared to those on existingmodels. We then supersymmetrize some of these models. Using N=1 superspacelanguage in extra dimensions, we find space-dependent flat directions which canbe used to localize fields. Finally, we discuss methods of breakingsupersymmetry and the impact of these models on the superpartner spectrum.