Yukawa Textures and Anomalies
  We augment the Minimal Supersymmetric Standard Model with a gauged family-dependent $U(1)$ to reproduce Yukawa textures compatible with experiment. In the simplest model with one extra chiral electroweak singlet field, acceptable textures require this $U(1)$ to be anomalous. The cancellation of its anomalies by a generic Green-Schwarz mechanism requires $\sin^2\theta_w=3/8$ at the string scale, suggesting a superstring origin for the standard model. 
Pierre Binetruy (Orsay) and Pierre Ramond (Univ Florida, Gainesville)