Collider Search Constraints on Singlet-Doublet Fermionic Dark Matter Model

Abstract

Dark matter (DM) physics is one of the major areas of recent particle physics research. Even after finding hints from rotational curves, inhomogeneities in CMBR, bullet cluster and indirect evidence from astrophysics, the exact nature of DM is still unknown. Particle physics research for DM has been guided by postulating DM primarily as a weakly interacting massive particle (WIMP) which freezes out from equilibrium distribution in the early universe and contributes to the observed relic density. The spin of the DM is completely unconstrained. In this thesis, we took up a minimal fermionic mixing DM model of a standard model(SM) SU(2) singlet and a doublet that already has been proposed in the literature and updated the allowed parameter space under relic density criteria and recent direct search experiment, PandaX. We studied in details the prospect of discovering it at the Large Hadron Collider for multilepton final state with 2, 3 and 4 leptons using monte carlo simulation methods. The analysis is done for few benchmark points in the parameter space allowed by relic density and direct detection criteria. We obtained that this model is very difficult to detect in future LHC runs at high luminosity due to heavy background from SM processes. But the significant region of the parameter space can still be tested for displaced charged vertex at LHC.