Abstract
CERN-LHC, ATLAS. A search for dark matter in the context of a two-Higgs-doublet model together with an additional pseudo-scalar mediator, which decays to the dark matter particles is presented. Processes where the pseudo-scalar mediator is produced in association with a single top quark are explored for the first time at the LHC. Several final states are considered, including either one or two charged leptons (electrons or muons) and a significant amount of missing transverse momentum. The analysis is based on the data collected with the ATLAS experiment at √s = 13 TeV during LHC Run 2 (2015-2018), corresponding to an integrated luminosity of 139 fb -1.
