YUKAWA TEXTURES WITH AN ANOMALOUS HORIZONTAL ABELIAN SYMMETRY

The observed hierarchy of quark and lepton masses and mixings may be o btained by adding an abelian family symmetry to the Minimal Supersymme tric Model and coupling quarks and leptons to an electroweak singlet s calar field. In a large class of such models, this symmetry suffers fr om anomalies which must be compensated by the Green-Schwarz mechanism; this in turn fixes the electroweak mixing angle to be sin(2) theta(W) = 3/8 at the string scale, without any assumed GUT structure, The ana lysis is extended to two distinct generalizations of the Standard Mode l: neutrino masses and mixings and R-parity violating interactions.