Neutralino dark matter and other LHC predictions from quasi Yukawa unification

Abstract

We explore the dark matter and LHC implications of t−b−τ quasi Yukawa unification in the framework of supersymmetric models based on the gauge symmetry G=SU(4)c×SU(2)L×SU(2)R. The deviation from exact Yukawa unification is quantified by a dimensionless parameter C (|C|≲0.2), such that the Yukawa couplings at MGUT are related by yt:yb:yτ=|1+C|:|1−C|:|1+3C|. In contrast to earlier studies which focused on universal gaugino masses, we consider non-universal gaugino masses at MGUT that are compatible with the gauge symmetry G. Our results reveal a variety of neutralino dark matter scenarios consistent with the observations. These include stau and chargino coannihilation scenarios, the A-resonance scenario, as well as Higgsino dark matter solutions which are more readily probed by direct detection searches. The gluino mass is found to be ≲4 TeV, the stop mass is ≳2 TeV, while the first two family squarks and sleptons are of order 4–5 TeV and 3 TeV respectively.