Electroweak Symmetry Breaking and Singlino Dark Matter with Deflected Anomaly Mediation

Abstract

We investigate the phenomenology of the Nearly Minimal Supersymmetric Standard Model (nMSSM) in the deflected anomaly mediation scenario. We also include the Fayet-Iliopoulos D-term of the standard model gauge group. In the nMSSM, the mu term is replaced by the vacuum expectation value of the gauge singlet; therefore, there is no difficulty in generating the B-term of the SUSY breaking scale. Although the messenger sector is introduced, direct couplings between nMSSM fields and messenger sector fields are forbidden by the discrete symmetry. Therefore, the phenomenology at the weak scale does not depend on the detail of the messenger sector. We show that there are regions of parameter space in which electroweak symmetry breaking occurs successfully and the lightest Higgs is heavier than the LEP bound. We show that the gluino is light in this scenario. The lightest neutralino, which is mainly composed of a singlino, is a candidate for dark matter. The relic density explains the observed abundance of dark matter. The dark matter-nucleon scattering cross section satisfies the current limit from CDMS and XENON10 with a small value for the strange quark content of a nucleon.