On the Suppression of the Dark Matter-Nucleon Scattering Cross Section in the SE6SSM

Abstract

In the E6 inspired U(1)N extension of the minimal supersymmetric (SUSY) standard model (MSSM), a single discrete Z˜2H symmetry permits suppressing rapid proton decay and non-diagonal flavor transitions. If matter parity and Z˜2H symmetry are preserved in this SUSY model (SE6SSM), it may involve two dark matter candidates. In this article, we study a new modification of the SE6SSM in which the cold dark matter is composed of gravitino and the lightest neutral exotic fermion. We argue that, in this case, the dark matter nucleon scattering cross-section can be considerably smaller than the present experimental limit.