相关论文: Unstable Gravitino Dark Matter and Neutrino Flux
Supersymmetric scenarios where the lightest superparticle (LSP) is the gravitino are an attractive alternative to the widely studied case of a neutralino LSP. A strong motivation for a gravitino LSP arises from the possibility of achieving…
We propose a consistent scenario of the evolution of the universe based on the large cutoff supergravity (LCSUGRA) hypothesis of supersymmetry breaking, where the gravitino and sfermion become as heavy a $\sim O(1-10 {\rm TeV})$. With such…
We study gravitino dark matter and slow gravitino decays within the framework of R-violating supersymmetry, with particular emphasis on the flavour dependence of the branching ratios and the allowed R-violating couplings. The dominant decay…
I report on some scenarios where the gravitino is the dark matter and the supersymmetry breaking mediated by a gauge sector.
We point out that there is no cosmological gravitino problem in a certain class of gauge-mediated supersymmetry-breaking (GMSB) models. The constant term in the superpotential naturally causes small mixings between the standard-model and…
We make use of the phase space density approach to discuss gravitino as a warm dark matter candidate. Barring fine tuning between the reheat temperature in the Universe and superparticle masses, we find that \emph{warm} gravitinos have both…
We consider the simplest class of the R-invariant gauge mediation model with the gravitino mass in the one to ten keV range. We show that the entropy production from the supersymmetry breaking sector makes the gravitino into a warm dark…
We discuss neutrino parameters in addition with the effects of a Higgs boson of mass $\sim$ 125 GeV in Split Supersymmetry with Bilinear R-Parity Violation. This model allows for the explanation of neutrino masses and mixing angles, and has…
We explore an alternative mechanism for the production of gravitino dark matter whereby relic gravitinos originate from the decays of superpartners which are still in thermal equilibrium, i.e. via freeze-in. Contributions to the gravitino…
We motivate Higgsino dark matter from a solution to the cosmological moduli/gravitino problem. Cosmological moduli/gravitino should be heavy enough to decay before the onset of Big Bang Nucleosynthesis, and this requirement typically forces…
The production and the final abundance of gravitino dark matter appear to depend crucially on the restoration of the global U(1) $R$-symmetry of GMSB sectors in a threefold way. An $R$-symmetric phase effectively suppresses the production…
The presence of high reheating temperatures in the thermal history of the universe challenges supersymmetric scenarios owing to the gravitino problem. We revise a general R-parity conserving gravitino dark matter scenario with a stau as the…
We show that, if decaying gravitino dark matter is responsible for the PAMELA and ATIC/PPB-BETS anomalies in the cosmic-ray electron and positron fluxes, both a reheating temperature and a gluino mass are constrained from above. In…
We analyze the cosmic-ray signatures of decaying gravitino dark matter in a model independent way based on an operator analysis. Thermal leptogenesis and universal boundary conditions at the GUT scale restrict the gravitino mass to be below…
Recent positron flux fraction measurements in cosmic-rays (CR) made by the AMS-02 satellite confirm and extends the evidence on the existence of a new (yet unknown) source of high energy positrons. To explain this excess, we use the…
A very simple way to obtain comparable baryon and DM densities in the early Universe is through their contemporary production from the out-of-equilibrium decay of a mother particle, if both populations are suppressed by comparably small…
It has been shown that very light or even massless neutralinos are consistent with all current experiments, given non-universal gaugino masses. Furthermore, a very light neutralino is consistent with astrophysical bounds from supernov{\ae}…
We consider cosmological implications of supersymmetric models with right-handed (s)neutrinos where the neutrino masses are purely Dirac-type. We pay particular attention to the case where gravitino is the lightest superparticle while one…
We implement the asymmetric dark matter framework, linking the ordinary and dark matter abundances, within a supersymmetric context. We consider a supersymmetric model that respects an approximate $U(1)_R$ symmetry, which is broken in such…
We show that gravitinos produced by decays of a supersymmetry breaking scalar field (the pseudo-moduli field) can naturally explain the observed abundance of dark matter in a certain class of the gauge mediation models. We study the decay…