D-term challenges for supersymmetric gauged Abelian flavor symmetries

Abstract

Attention is called to potentially dangerous lepton-flavor violation (LFV) induced by the D-terms of additional U(1) flavor-dependent gauge symmetries in supersymmetric models. In such models, LFV persists despite an arbitrarily high scale for the U(1) breaking and despite arbitrarily small gauge couplings. In light of recent experimental observations of neutrino oscillations, these models are highly motivated experimentally and theoretically. Taking into account also the recent measurement of the muon anomalous magnetic moment, strong bounds are calculated for the magnitude of the D-term-induced LFV. Using current data we find that the slepton mass-mixing parameter (m_{\tilde l_L}^2)_{12}/m_{\tilde l_L}^2 is required to be less than O(10^{-4}) -- a value perhaps already too low compared to expectations. Near future probes will increase sensitivity to 10^{-6}.