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We extend our previous studies of the neutrino fluxes expected from neutralino LSP annihilations inside the Sun to include variants of the minimal supersymmetric extension of the Standard Model (MSSM) with squark, slepton and gaugino masses constrained to be universal at the GUT scale, but allowing one or two nonuniversal supersymmetry breaking parameters contributing to the Higgs masses (NUHM 1,2). As in the constrained MSSM (CMSSM) with universal Higgs masses, there are large regions of the NUHM parameter space where the LSP density inside the Sun is not in equilibrium, so that the annihilation rate may be far below the capture rate, and there are also large regions where the capture rate is not dominated by spin-dependent LSP-proton scattering. The spectra possible in the NUHM are qualitatively similar to those in the CMSSM. We calculate neutrino-induced muon fluxes above a threshold energy of 10 GeV, appropriate for the IceCube/DeepCore detector, for points where the NUHM yields the correct cosmological relic density for representative choices of the NUHM parameters. We find that the IceCube/ DeepCore detector can probe regions of the NUHM parameter space in addition to analogues of the focus point strip and the tip of the coannihilation strip familiar from the CMSSM. These include regions with enhanced Higgsino-gaugino mixing in the LSP composition, that occurs where neutralino mass eigenstates cross over. On the other hand, rapid-annihilation funnel regions in general yield neutrino fluxes that are unobservably small. [ABSTRACT FROM AUTHOR]

We study a minimal extension of the Standard Model where a scalar field is coupled to the right-handed neutrino responsible for the seesaw mechanism for neutrino masses. In the absence of other couplings, below 8 TeV the scalar A has a unique decay mode A → νν, ν being the physical observed light neutrino state. Above 8 TeV (11 TeV), the 3-body (4-body) decay modes dominate. Imposing constraints on neutrino masses mν from atmospheric and solar experiments implies a long lifetime for A, much larger than the age of the Universe, making it a natural dark matter candidate. Its lifetime can be as large as 1029 seconds, and its signature below 8 TeV would be a clear monochromatic neutrino signal, which can be observed by ANTARES or IceCube. Under certain conditions, the scalar A may be viewed as a Goldstone mode of a complex scalar field whose vacuum expectation value generates the Majorana mass for νR. In this case, we expect the dark matter scalar to have a mass ≲ 10 GeV. [ABSTRACT FROM AUTHOR]

No-scale supergravity provides a successful framework for Starobinsky-like inflation models. Two classes of models can be distinguished depending on the identification of the inflaton with the volume modulus, T (C models), or a matterlike field, (WZ models). When supersymmetry is broken, the inflationary potential may be perturbed, placing restrictions on the form and scale of the supersymmetry breaking sector. We consider both types of inflationary models in the context of high-scale supersymmetry. We further distinguish between models in which the gravitino mass is below and above the inflationary scale. We examine the mass spectra of the inflationary sector. We also consider, in detail, mechanisms for leptogenesis for each model when a right-handed neutrino sector, used in the seesaw mechanism to generate neutrino masses, is employed. In the case of C models, reheating occurs via an inflaton decay to two Higgs bosons. However, there is a direct decay channel to the lightest right-handed neutrino which leads to nonthermal leptogenesis. In the case of WZ models, in order to achieve reheating, we associate the matterlike inflaton with one of the right-handed sneutrinos whose decay to the lightest right-handed neutrino simultaneously reheats the Universe and generates the baryon asymmetry through leptogenesis. [ABSTRACT FROM AUTHOR]

We propose a model where a long-lived pseudoscalar EeV particle can be produced with sufficient abundance so as to account for the cold dark matter density, despite having a Planck mass suppressed coupling to the thermal bath. Connecting this state to a hidden sterile neutrino sector through derivative couplings, induced by higher dimensional operators, allows one to account for light neutrino masses while having a lifetime that can be much larger than the age of the Universe. Moreover, the same derivative coupling accounts for the production of dark matter in the very first instant of the reheating. Given the sensitivity of the IceCube and ANITA collaborations, we study the possible signatures of such a model in the form of ultrahigh-energy cosmic rays in the neutrino sector, and show that such signals could be detected in the near future. [ABSTRACT FROM AUTHOR]

We revisit the limits on R -parity violation in the minimal supersymmetric standard model. In particular, we focus on the high-scale supersymmetry scenario in which all the sparticles are in excess of the inflationary scale of approximately 1013 GeV, and thus no sparticles ever come into thermal equilibrium. In this case, the cosmological limits, stemming from the preservation of the baryon asymmetry that have been previously applied for weak-scale supersymmetry, are now relaxed. We argue that even when sparticles are never in equilibrium, R-parity violation is still constrained via higher dimensional operators by neutrino and nucleon experiments and/or insisting on the preservation of a nonzero B - L asymmetry. [ABSTRACT FROM AUTHOR]