Wino cold dark matter from anomaly mediated SUSY breaking

Abstract

The cosmological moduli problem is discussed in the framework of sequestered sector/anomaly-mediated supersymmetry (SUSY) breaking. In this scheme, the gravitino mass (corresponding to the moduli masses) is naturally 10 − 100 TeV, and hence the lifetime of the moduli fields can be shorter than ∼ 1 sec. As a result, the cosmological moduli fields should decay before big-bang nucleosynthesis starts. Furthermore, in the anomaly-mediated scenario, the lightest superparticle (LSP) is the Wino-like neutralino. Although the large annihilation cross section means the thermal relic density of the Wino LSP is too small to be the dominant component of cold dark matter (CDM), moduli decays can produce Winos in sufficient abundance to constitute CDM. If Winos are indeed the dark matter, it will be highly advantageous from the point of view of detection. If the halo density is dominated by the Wino-like LSP, the detection rate of Wino CDM in Ge detectors can be as large as 0.1 − 0.01 event/kg/day, which is within the reach of the future CDM detection with Ge detector. Furthermore, there is a significant positron signal from pair annihilation of Winos in our galaxy which should give a spectacular signal at AMS. *

Revisiting top–bottom-tau Yukawa unification in supersymmetric grand unified theories

“…Fortunately this is not the case. Non-thermal production of the lightest neutralino via late-time gravitino [20] or moduli [21] decays works surprisingly well and is easily compatible with the right amount of cold dark matter needed to explain astrophysical observations. …”

Probing light higgsinos in natural SUSY from monojet signals at the LHC

“…This makes the standard thermally produced WIMP dark matter inadequate in the natural MSSM. In order to provide the required relic density, several alternative ways have been proposed [60][61][62][63][64][65], such as choosing the axion-higgsino admixture as the dark matter [66,67]. In this case, the spin-independent neutralino-proton scattering cross section σ SI p must be re-scaled by a factor Ωχ0 1 h 2 /Ω PL h 2 [66,67], where Ω PL h 2 is the relic density measured by Planck satellite [68].…”

Thermal effects on saxion in supersymmetric model with Peccei–Quinn symmetry

“…However, such a difficulty can be avoided with large enough pair annihilation cross section of the LSP. This is the case, for example, if the LSP is the neutral Wino [18]. If the saxion dominantly decays into MSSM particles, one should take account of the entropy production due to the saxion decay.…”