Gravitino dark matter and general neutralino NLSP

Axino arises in supersymmetric versions of axion models and is a natural candidate for cold or warm dark matter. Here we revisit axino dark matter produced thermally and non-thermally in light of recent developments. First we discuss the definition of axino relative to low energy axion one for several KSVZ and DFSZ models of the axion. Then we review and refine the computation of the dominant QCD production in order to avoid unphysical cross-sections and, depending on the model, to include production via SU(2) and U(1) interactions and Yukawa couplings.

Section: Jhep04(2012)106mentioning

confidence: 99%

Axino cold dark matter revisited

Choi

Covi

Kim

et al. 2012

“…We include it here for the purpose of comparison with the other representative points. The SUG0 point could also respect the dark matter constraint without changing the EW fine-tuning significantly, for example by adding a small amount of R-parity violation causing the LSP to decay [22,23], or if the true dark matter consists of axions/axinos [24,25].…”

Section: Jhep05(2011)120mentioning

confidence: 99%

Fine-tuning implications for complementary dark matter and LHC SUSY searches

Cassel

Ghilencea

Kraml

et al. 2011

The requirement that SUSY should solve the hierarchy problem without undue fine-tuning imposes severe constraints on the new supersymmetric states. With the MSSM spectrum and soft SUSY breaking originating from universal scalar and gaugino masses at the Grand Unification scale, we show that the low-fine-tuned regions fall into two classes that will require complementary collider and dark matter searches to explore in the near future. The first class has relatively light gluinos or squarks which should be found by the LHC in its first run. We identify the multijet plus E miss T signal as the optimal channel and determine the discovery potential in the first run. The second class has heavier gluinos and squarks but the LSP has a significant Higgsino component and should be seen by the next generation of direct dark matter detection experiments. The combined information from the 7 TeV LHC run and the next generation of direct detection experiments can test almost all of the CMSSM parameter space consistent with dark matter and EW constraints, corresponding to a fine-tuning not worse than 1:100. To cover the complete low-fine-tuned region by SUSY searches at the LHC will require running at the full 14 TeV CM energy; Open Access doi:10.1007/JHEP05(2011)120 JHEP05(2011)120in addition it may be tested indirectly by Higgs searches covering the mass range below 120 GeV.

“…[58] for the implementation of BBN constraints, which mainly depend on the LOSP mass m LOSP and abundance Ω LOSP h 2 , as well as on the LOSP hadronic branching ratio B h . We calculate Ω LOSP h 2 as described in section 3.1 and for B h we use existing results for neutralinos [61], sneutrinos [62] and charged sleptons [63].…”

Section: Jhep11(2014)146mentioning

confidence: 99%

“…In this case, however, Ω LOSP h 2 (high T R ) typically exceeds unity and B h ∼ 1; hence, in order to avoid bounds from the BBN one can simply require the LOSP lifetime to be 0.1 s, which leads to [61] …”

Section: Jhep11(2014)146mentioning

confidence: 99%

Neutralino and gravitino dark matter with low reheating temperature

Roszkowski

Trojanowski

Turzyński

2014

We examine a scenario in which the reheating temperature T R after inflation is so low that it is comparable to, or lower than, the freeze out temperature of ordinary WIMPs. In this case the relic abundance of dark matter is reduced, thus relaxing the impact of the usually strong constraint coming from the requirement that the universe does not overclose. We first re-examine the dynamics of freezeout during reheating. Next we study the parameter space of the MSSM with ten free parameters, the Constrained MSSM and the singlino-dominated regions of the Next-to-MSSM. In each case we often find dramatic departures from the usually considered regime of high T R , with important implications for direct detection dark matter searches. In particular, in the MSSM we examine WIMP mass range up to about 5 TeV, and we find large regions of bino dark matter over the whole mass range, and of higgsino dark matter with mass over a similar range but starting from the ∼ 1 TeV value of the standard high T R scenario. We show that the prospects for bino detection strongly depend on T R , while the higgsino is for the most part detectable by future one-tonne detectors. The wino, which is excluded in the standard scenario, becomes allowed again if its mass is roughly above 3.5 TeV, and can also be partially detectable. In the CMSSM, the bino and higgsino mass ranges become much more constrained although detection prospects remain roughly similar. In the Next-to-MSSM we show that, at low enough T R wide ranges of singlino-dominated parameter space of the model become again cosmologically allowed, although detection prospects remain nearly hopeless. We also study the non-thermal contribution to the DM relic density from direct and cascade decays of the inflaton. Finally, in the framework of the MSSM we consider the case of a gravitino as dark matter. In this case we find strong bounds from overclosure and from Big Bang Nucleosynthesis, and derive lower limits on T R which depend on the gravitino mass and on the nature of the lightest ordinary superpartner.