Supersymmetry Hierarchy Problems and Anomalous Horizontal U(1) Symmetry
  It is suggested that various hierarchy problems in supersymmetric standard model, i.e. the Yukawa hierarchies, the \mu problem, and the suppression of dangerous baryon and/or lepton number (B/L) violating couplings, are resolved altogether in the framework of horizontal U(1) symmetry whose spontaneous breaking results in the appearance of one expansion parameter (the Cabibbo angle). Within a reasonable range of U(1) charges, there exist a few models compatible with experiments. The specific sizes of B/L violating couplings of these models are calculated and several phenomenological consequences are discussed. 
Kiwoon Choi, Eung Jin Chun and Hyungdo Kim