Related papers: Axinos as Cold Dark Matter
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…
While supersymmetric models provide a solution to the big hierarchy problem, natural SUSY is also allowed by the little hierarchy problem. In supersymmetric models which include the Peccei-Quinn (PQ) solution to the strong CP problem, one…
We investigate the detectability of axino-like particle, which is defined as a supersymmetric partner of axion-like particle and can be a good candidate for dark matter in our Universe. Especially, we consider the fixed target experiments…
The baryonic and cold dark matter are reviewed in the context of cosmological models. The theoretical search for the particle candidates is limited by supersymmetric extension of the Standard Model. Generically in such models there are just…
We revisit the cosmology of the supersymmetric QCD axion, highlighting the existence of a serious cosmological axino problem that is fully analogous to the gravitino problem of overclosure via thermal production. A general analysis implies…
In theories with a gauge-mediated mechanism of supersymmetry breaking the gravitino is likely to be the lightest superparticle and, hence, a candidate for dark matter. We show that the decay of the next-to-lightest superparticle into a…
The possibility of the CDM axino is presented. From the early days of supersymmetry, axino has been considered as hot dark matter and warm dark matter. But the CDM axino has been considered quite recently. It is because the low reheating…
Gravitinos and axinos produced in the late decays of other supersymmetric particles are well-motivated dark matter (DM) candidates, whose experimental evidences are very distinctive and different from other standard candidates, as thermal…
In the supersymmetric (SUSY) standard model, the lightest neutralino may be the lightest SUSY particle (LSP), and it is is a candidate of the dark matter in the universe. The LSP dark matter might be produced by the non-thermal process such…
We consider supersymmetric (SUSY) models wherein the strong CP problem is solved by the Peccei-Quinn (PQ) mechanism with a concommitant axion/axino supermultiplet. We examine R-parity conserving models where the neutralino is the lightest…
The viability of a possible cosmological scenario is investigated. The theoretical framework is the constrained next-to-minimal supersymmetric standard model (cNMSSM), with a gravitino playing the role of the lightest supersymmetric…
Both the naturalness of the electroweak symmetry breaking and the resolution of the strong CP problem may require a small Higgsino mass $\mu$ generated by a realization of the DFSZ axion model. Assuming the axino is the lightest…
We point out that the axino predicted as the supersymmetric partner of the axion is a good candidate for the recently proposed sterile neutrino cool dark matter. The axino mass falls into the right range in the context of gauge mediated…
Gravitino is one feasible candidate for the dark matter in supergravity models. With its couplings being suppressed by the Plank mass, gravitino interacts very weakly with other particles, making its direct detection, or production at…
The gravitino is a promising candidate for cold dark matter. We study cosmological constraints on scenarios in which the gravitino is the lightest supersymmetric particle and a charged slepton the next-to-lightest supersymmetric particle…
We study the neutralino being the Lightest Supersymmetric Particle (LSP) as a cold Dark Matter (DM) candidate with a mass less than 40 GeV in the framework of the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM). We find that with the…
The axino dark matter hypothesis in RSII brane model is studied. Within the framework of CMSSM we assume that the lightest neutralino or stau is the NLSP, and that the axino production has a single contribution from the NLSP decay. It is…
In a large class of supersymmetric (SUSY) axion model the mass of axino $\axino$ (a fermionic superpartner of the axion) is predicted as $m_{\axino} \lesssim {\cal O}(1)$ keV. Thus, the axino is the lightest SUSY particle (LSP). We pointed…
We analyze the mass of the axino, the fermionic superpartner of the axion, in general supergravity models incorporating a Peccei--Quinn--symmetry and determine the cosmological constraints on this mass. In particular, we derive a simple…
Many extensions of the Standard Model predict super-weakly interacting particles, which typically have to decay before Big Bang Nucleosynthesis (BBN). The entropy produced in the decays may help to reconcile thermal leptogenesis and BBN in…