Search

We present ψ′MSSM, a model based on a U(1)ψ′ extension of the minimal supersymmetric standard model. The gauge symmetry U(1)ψ′, also known as U(1)N, is a linear combination of the U(1)χ and U(1)ψ subgroups of E6. The model predicts the existence of three sterile neutrinos with masses ≳0.1 eV, if the U(1)ψ′ breaking scale is of order 10 TeV. Their contribution to the effective number of neutrinos at nucleosynthesis is ΔNν ≃ 0.29. The model can provide a variety of possible cold dark matter candidates including the lightest sterile sneutrino. If the U(1)ψ′ breaking scale is increased to 10³ TeV, the sterile neutrinos, which are stable on account of a Z2 symmetry, become viable warm dark matter candidates. The observed value of the standard model Higgs boson mass can be obtained with relatively light stop quarks thanks to the D-term contribution from U(1)ψ′. The model predicts diquark and diphoton resonances which may be found at an updated LHC. The well-known μ problem is resolved and the observed baryon asymmetry of the universe can be generated via leptogenesis. The breaking of U(1)ψ′ produces superconducting strings that may be present in our galaxy. A U(1) R symmetry plays a key role in keeping the proton stable and providing the light sterile neutrinos. [ABSTRACT FROM AUTHOR]

We show how successful supersymmetric hybrid inflation is realized in realistic models where the resolution of the minimal supersymmetric standard model µ problem is intimately linked with axion physics. The scalar fields that accompany the axion, such as the saxion, are closely monitored during and after inflation to ensure that the axion isocurvature perturbations lie below the observational limits. The scalar spectral index n s ≃ 0.96 - 0.97, while the tensor-to-scalar ratio r, a canonical measure of gravity waves, lies well below the observable range in our example. The axion domain walls are inflated away, and depending on the axion decay constant f a and the magnitude of the µ parameter, the axions and/or the lightest supersymmetric particle compose the dark matter in the Universe. Nonthermal leptogenesis is naturally implemented in this class of models. [ABSTRACT FROM AUTHOR]