On the Viability of Thermal Well-Tempered Dark Matter in SUSY GUTs

Abstract

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 context of supersymmetric grand unified theories with third family Yukawa coupling unification. A global chi^2 analysis is performed, including the observables MW, MZ, GF, alpha_em, alpha_s(MZ), Mt, mb(mb), Mtau, b -> s gamma, BR(Bs -> mu^+ mu^-), Mh and Omegah^2. Tensions in simultaneously fitting the Higgs and bottom quark masses while also avoiding gluino mass bounds from the LHC disfavors light Higgsinos with mass < 500 GeV, ruling out light Bino/Higgsino dark matter candidates. Bino/Wino/Higgsino and Bino/Wino candidates fare somewhat better although they are fine-tuned and require departure from GUT scale gaugino mass universality (the example chosen here is the mixed modulus-anomaly pattern). Implications for dark matter direct detection of these models as well as collider signatures are briefly discussed. Independent of the thermal dark matter viability, these models will be severely constrained by the absence of a gluino at the next run of LHC.