Exploring Fermionic Dark Matter in the Presence of Scalar Leptoquarks

Abstract: We study an extension of the vector-like lepton dark matter model by introducing scalar leptoquarks that modify the properties of the vector-like lepton dark matter candidate, helping it evade stringent direct detection constraints. In the minimal setup, the neutral component of a pure $SU(2)$ doublet vector-like lepton fails to simultaneously account for the observed relic abundance while remaining consistent with current direct detection limits. We show that the addition of the scalar leptoquarks can induce corrections to the mass of the vector-like lepton dark matter, splitting it into two non-degenerate pseudo-Dirac states. This mass splitting can help evade the direct detection bounds naturally. In addition, the extended setup also opens up a larger parameter space of the model that can accommodate the correct relic density.