Related papers: Very Light Gravitino Dark Matter
In this paper, we discuss interesting scenarios resulting from the interplay between the gravitino and the lightest right-handed (s)neutrino. We consider two gravitino mass regimes vastly separated, that is, $m_{3/2}=\mathcal{O}(100){\rm…
We study the production of spin 1/2 gravitinos in a thermal Universe. Taking into account supersymmetry breaking due to the finite thermal energy density of the Universe, there is a large enhancement in the cross section of production of…
We present a class of models in the framework of gauge mediation supersymmetry breaking where the standard model is supplemented by additional U(1) symmetry which acts only on the third generation fermions. The messenger fields carry…
New particles in theories beyond the standard model can manifest as stable relics that interact strongly with visible matter and make up a small fraction of the total dark matter abundance. Such particles represent an interesting physics…
In a recent paper, we proposed the possibility that supersymmetry breaking is communicated dominantly via a U(1)' vector multiplet. We also required that the U(1)' plays a crucial role in solving the mu problem. We discuss here in detail…
Scenarios where gravitinos with GeV masses make up dark matter are known to be in tension with high reheating temperatures, as required by e.g. thermal leptogenesis. This tension comes from the longevity of the NLSPs, which can destroy the…
We show that when the supersymmetric SU(5) model is extended to explain small neutrino masses by the type III seesaw mechanism, the new {\bf 24}-dimensional fields needed for the purpose can act as messengers for transmitting SUSY breaking…
In this research we consider a $U(1)_X$ gauge boson acting as a dark matter candidate. The vector dark matter (DM) gets mass when a complex singlet scalar breaks the gauge symmetry spontaneously, adding a second Higgs boson to the spectra.…
We consider a simple class of models in which the dark matter, X, is coupled to a new gauge boson, phi, with a relatively low mass (m_phi \sim 100 MeV-3 GeV). Neither the dark matter nor the new gauge boson have tree-level couplings to the…
We investigate the dark matter prospects of supersymmetric models with nonuniversal gaugino masses. We find that for very particular values of the ratio of soft supersymmetry-breaking gaugino masses, M2/M1, an enhanced coannihilation…
The gravitino may well play an important role in cosmology, not only because its interactions are Planck-suppressed and therefore long-lived, but also because it is copiously produced via various processes such as particle scatterings in…
We review the phenomenology of SUSY dark matter in various versions of MSSM, with universal and nonuniversal gaugino masses at the GUT scale. We start with the universal case (CMSSM), where the cosmologically compatible dark matter relic…
We study the direct detection prospects for a representative set of simplified models of sub-GeV dark matter (DM), accounting for existing terrestrial, astrophysical and cosmological constraints. We focus on dark matter lighter than an MeV,…
We construct a gauge-mediation model with a D-term supersymmetry (SUSY) breaking. R-symmetry breaking necessary for generating the SUSY standard-model gaugino masses is given by gaugino condensation of a strongly coupled gauge theory in the…
An unstable gravitino with lifetime longer than $10^{26}$ sec or so has been proposed as a possible dark matter candidate in supergravity models with R-parity breaking. We find a natural realization of this idea in the minimal…
The cosmological significance of the neutralino sector is studied for a class of models in which electroweak symmetry breaking is seeded by a gauge singlet. Extensive use is made of the renormalisation group equations to significantly…
We show that an oscillating scalar field in supergravity of mass of the order of $\sim$ TeV with a nonzero vacuum expectation value ($\sim 10^{10}$ GeV) can be a candidate of cold dark matter (CDM). To avoid the gravitino problem, we need a…
The `$\mu$ from $\nu$' supersymmetric standard model ($\mu\nu$SSM) solves the $\mu$ problem of supersymmetric models and reproduces neutrino data, simply using couplings with the three families of right-handed neutrinos $\nu$'s. Novel…
A new scheme for lightest supersymmetric particle (LSP) dark matter is introduced and studied in theories of TeV supersymmetry with a QCD axion, $a$, and a high reheat temperature after inflation, $T_R$. A large overproduction of axinos…
A rather minimal possibility is that dark matter consists of the gauge bosons of a spontaneously broken symmetry. Here we explore the possibility of detecting the gravitational waves produced by the phase transition associated with such…