Related papers: Axinos as Dark Matter
Supersymmetric extensions of the Standard Model with scalar superpartners above 10 TeV are well motivated since the Higgs boson mass can be explained by quantum corrections while maintaining gauge coupling unification. If supersymmetry…
In a scenario with heavy supersymmetric sfermions and decoupled supersymmetric Higgs sector, a well tempered neutralino is the remaining candidate for thermal single-component sub-TeV dark matter. Well tempered neutralinos are studied in…
The parameters of the Minimal Supersymmetric Standard Model appear to require uncomfortably precise adjustment in order to reconcile the electroweak symmetry breaking scale with the lower mass limits on a neutral Higgs scalar boson. This…
Some particle candidates for dark matter are reviewed in the light of recent experimental and theoretical developments. Models for massive neutrinos are discussed in the light of the recent atmospheric-neutrino data, and used to motivate…
The heavy sfermion scenario is naturally realized when supersymmetry breaking fields are charged under some symmetry or are composite fields. There, scalar partners of standard model fermions and the gravitino are as heavy as O(10-1000) TeV…
We study the possibility of mixed dark matter obtained through the phase space distribution of a single particle. An example is offered in the context of SUSY models with a Peccei-Quinn symmetry. Axinos in the 100 keV range can naturally…
If a bosonic partner of a right-handed neutrino dominates the early universe sufficiently before its decay, important ingredients in the present universe are related to physics of the right-handed neutrino sector. In particular, we find…
We introduce four supersymmetric (SUSY) axion models in which the strong CP problem and the $\mu$ problem are solved with the help of the Peccei-Quinn mechanism and the Kim-Nilles mechanism, respectively. The axion physics enriches the SUSY…
Among various supersymmetric (SUSY) models, gauge-mediated SUSY breaking models with an ultra-light gravitino of mass m_{3/2} \lesssim O(10) eV are very attractive, since they are completely free from notorious gravitino problems. A…
We examine the minimal supergravity (mSUGRA) model under the assumption that the strong CP problem is solved by the Peccei-Quinn mechanism. In this case, the relic dark matter (DM) abundance consists of three components: {\it i}). cold…
We consider axino dark matter in large R-parity violation (RPV). In moduli-dominated universe, axino is produced thermally or non-thermally via saxion decay, then late-decaying moduli dilute axino density, which results in the right…
After a brief review of the axion solution of the strong CP problem, its supersymmetric extension and the superstring axion are discussed. I also present one interesting cosmological scenario, the axino-gravitino cosmology, for the large…
One intriguing BSM particle is the QCD axion, which could simultaneously provide a solution to the Strong CP problem and account for some, if not all, of the dark matter density in the universe. This particle is a pNGB of the conjectured…
SuperWeakly-Interacting Massive Particles (superWIMPs) produced in the late decays of other particles are well-motivated dark matter candidates and may be favored over standard Weakly-Interacting Massive Particles (WIMPs) by small scale…
Cosmologically long-lived, composite states arise as natural dark matter candidates in theories with a strongly interacting hidden sector at a scale of 10 - 100 TeV. Light axion-like states, with masses in the 1 MeV - 10 GeV range, are also…
After a short introduction on particle candidates for dark matter within possible extensions of the standard model, we concentrate on Weakly Interacting Massive Particles, and on one of their most interesting physical realizations: the…
Although the standard {\Lambda}CDM model describes the cosmic microwave background radiation and the large scale structure of the Universe with great success, it has some tensions with observations in the effective number of neutrino…
We consider the possibility that the gravitino might be the lightest supersymmetric particle (LSP) in the constrained minimal extension of the Standard Model (CMSSM). In this case, the next-to-lightest supersymmetric particle (NSP) would be…
We present an updated analysis of the constrained minimal supersymmetric standard model with mu>0 supplemented by an `asymptotic' Yukawa coupling quasi-unification condition, which allows an acceptable b-quark mass. Imposing constraints…
The Axion is a particle arising from the Peccei-Quinn solution to the strong CP problem. Peccei-Quinn symmetry breaking in the early universe could produce a large number of axions which would still be present today, making the axion a…