Anomalous U(1) Gauge Symmetry and Lepton Flavor Violation

Last few years, many people have studied the possibilities that the anomalous U(1) gauge symmetry is a trigger of SUSY breaking and/or an origin of the fermion mass hierarchy. Though it is interesting that the anomalous U(1) symmetry may explain the above two phenomena simultaneously, it causes a negative stop mass squared or a severe fine-tuning in order to avoid the FCNC problem. Recently it was pointed out that the F -term contribution of the dilaton field can dominate the anomalous U(1) D-term contribution which induces flavor-dependent scalar masses, so that the FCNC problem may be naturally avoided. In this paper, we study the case that the dilaton is stabilized by the deformation of the Kähler potential for the dilaton and find that the order of the ratio between the F -term and the D-term contributions is generally determined. It means that the branching ratio of μ → eγ can be found around the present experimental bound. a e-mail: [email protected], [email protected] b He is visiting TU from Oct.98 to Sep. 99. e-mail: [email protected]