Search for Dark Matter Produced in Association With a Higgs Boson in the Four Leptons Final State Using Run II Data at √s = 13 TeV With the CMS Experiment

This thesis presents the search for dark matter candidates produced in association with a Higgs boson. The search is performed using proton proton collision data collected by CMS experiment during Run II and corresponding to a total integrated luminosity of 137 fb􀀀1 at center of mass energy of 13 TeV. The Higgs boson decay channel considered in the search is the Higgs decay to a pair of Z bosons which decay to four leptons with three possible nal states (4 , 4e and 2e2 ). The experimental signature is characterized by signi cant amount of missing transverse energy pmiss T accompanied with four leptons from the Higgs decay products. This search is referred as \Mono-Higgs" search, where the Higgs boson is used as a candle to tag the presence of the dark matter candidate. The results obtained are interpreted in the context of the two Higgs doublet simpli ed model extended by light pseudoscalar. This model has been inspected with the Higgs ! ZZ ! 4l decay channel in CMS, for the st time.