This thesis presents a search for dark matter produced in association with top quarks in data collected by the CMS detector at the LHC, corresponding to 138 fb-1 of proton-proton collisions at a center-of-mass energy of 13 TeV. Production of dark matter particles in association with both a single top quark and a pair of top quarks are considered. The search is performed in three separate channels depending on the number of leptons in the final state, which include the all hadronic, single lepton, and dileptonic final states. The primary strategy of the search is to look for an excess of events with respect to the background-only prediction in events with a large imbalance in the transverse momentum. The results are interpreted in the context of a simplified model in which either a scalar or pseudoscalar mediator couples to top quarks and to dark matter fermions. Future prospects for improving the search are also discussed
Events
This thesis presents a search for dark matter produced in association with top quarks in data collected by the CMS detector at the LHC, corresponding to 138 fb-1 of proton-proton collisions at a center-of-mass energy of 13 TeV. Production of dark matter particles in association with both a single top quark and a pair of top quarks are considered. The search is performed in three separate channels depending on the number of leptons in the final state, which include the all hadronic, single lepton, and dileptonic final states. The primary strategy of the search is to look for an excess of events with respect to the background-only prediction in events with a large imbalance in the transverse momentum. The results are interpreted in the context of a simplified model in which either a scalar or pseudoscalar mediator couples to top quarks and to dark matter fermions. Future prospects for improving the search are also discussed