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High Energy Physics - Phenomenology, hep-ph
Abstract:
We re-examine the stop co-annihilation scenario of the Minimal Supersymmetric
Standard Model, wherein a bino-like lightest supersymmetric particle has a
thermal relic density set by co-annihilations with a scalar partner of the top
quark in the early universe. We concentrate on the case where only the top
partner sector is relevant for the cosmology, and other particles are heavy. We
discuss the cosmology with focus on low energy parameters and an emphasis on
the implications of the measured Higgs boson mass and its properties. We find
that the irreducible direct detection signal correlated with this cosmology is
generically well below projected experimental sensitivity, and in most cases
lies below the neutrino background. A larger, detectable, direct detection rate
is possible, but is unrelated to the co-annihilation cosmology. LHC searches
for compressed spectra are crucial for probing this scenario.