Bino Dark Matter and Big Bang Nucleosynthesis in the Constrained E6SSM with Massless Inert Singlinos

Abstract

We discuss a new variant of the E6 inspired supersymmetric standard model (E6SSM) in which the two inert singlinos are exactly massless and the dark matter candidate has a dominant bino component. A successful relic density is achieved via a novel mechanism in which the bino scatters inelastically into heavier inert Higgsinos during the time of thermal freeze-out. The two massless inert singlinos contribute to the effective number of neutrino species at the time of Big Bang Nucleosynthesis, where the precise contribution depends on the mass of the Z' which keeps them in equilibrium. For example for mZ' > 1300 GeV we find Neff \approx 3.2, where the smallness of the additional contribution is due to entropy dilution. We study a few benchmark points in the constrained E6SSM with massless inert singlinos to illustrate this new scenario.

24 pages, revised for publication in JHEP

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Cited by in corpus (10)

• GUT Physics in the era of the LHC
• Dark Matter in a Constrained $E_6$ Inspired SUSY Model
• Dark matter candidates in the constrained Exceptional Supersymmetric Standard Model
• Discovering $E_6$ SUSY models in gluino cascade decays at the LHC
• Higgs Bosons in supersymmetric U(1)' models with CP Violation
• Monophoton signals in electron-positron colliders in a simplified E6SSM
• Leptogenesis and Dark Matter-Nucleon Scattering Cross Section in the SE6SSM
• TeV-scale leptoquark searches at the LHC and their E${}_6$SSM Interpretation
• A combined approach to the analysis of space and ground experimental data within a simplified E6SSM
• Interactions of exotic neutralino dark matter with nucleons in $U(1)$ extensions of the MSSM originating from $E_6$ GUTs