Dark matter in the supersymmetric radiative seesaw model with an anomalous U(1) symmetry

The existence of an anomalous U(1) symmetry is shown to play a crucial role in the supersymmetric radiative seesaw model for neutrino masses. It explains the smallness of some couplings related to neutrino mass generation in a favorable way in addition to cause the hierarchical structure of Yukawa couplings of quarks and leptons. If it is spontaneously broken to a Z(2) subgroup, this Z(2) symmetry can make a lifetime of the lightest field with its odd parity extremely long. Thus, the model has an additional dark matter candidate other than the lightest neutralino, which appears in the R-parity conserved MSSM. We discuss the nature of dark matter by taking account of its relation to the neutrino mass generation and the lepton flavor violation. (C) 2011 Elsevier B.V. All rights reserved.