Reviving sub-TeV $$SU(2)_L$$ lepton doublet dark matter

Abstract

AbstractIn this work we study the hybrid kind of dark matter (DM) production mechanism where both thermal and non-thermal contribution at two different epochs set the DM relic abundance. This hybrid set up in turn shifts the parameter space of DM in contrast to pure thermal DM scenario. We review such production mechanism in the context of the$$SU(2)_L$$SU(2)Llepton doublet dark matter$$(\Psi )$$(Ψ)augmented with an additional singlet dark scalar (S). The neutral component of the dark doublet can serve as a stable DM candidate and in pure thermal scenario, it is under-abundant as well as excluded from direct detection constraints due to its strong gauge interactions in the sub-TeV mass regime. However, in addition to the thermal contribution, the late time non-thermal DM production from the decay of the long-lived dark scalarShelps to fulfill the deficit in DM abundance. On the other hand, the strong gauge mediated direct detection constraint can be evaded with the help of a$$SU(2)_L$$SU(2)Ltriplet scalar(with$$Y=2),$$Y=2),resulting a pseudo-Dirac DM. To realize our proposed scenario we impose a discrete$${\mathcal {Z}}_2$$Z2symmetry under which both$$\Psi $$ΨandSare odd while rest of the fields are even. We find the lepton doublet pseudo-Dirac DM with mass$$\sim 450{-}1200$$∼450-1200 GeV, compatible with the observed relic density, direct, indirect, and existing collider search constraints.