Fermion masses and gauge mediated supersymmetry breaking from a single U(1)

We present a supersymmetric model of flavor. A single U(1) gauge group is responsible for both generating the flavor spectrum and communicating supersymmetry breaking to the visible sector. The problem of flavor changing neutral currents is overcome, in part using an 'effective supersymmetry' spectrum among the squarks, with the first two generations very heavy. All masses are generated dynamically and the theory is completely renormalizable. The model contains a simple Froggatt-Nielsen sector and communicates supersymmetry breaking via gauge mediation without requiring a separate messenger sector. By forcing the theory to be consistent with SU(5) grand unification, the model predicts a large tanβ and a massless up quark. While respecting the experimental bounds on CP violation in the K system, the model leads to a large enhancement of CP violation in B-bar B mixing as well as in B decay amplitudes. copyright 1999 The American Physical Society