Search for Dark Matter Particles Predicted by the Scalar Portal Model with a Two-Doublet Expansion of Higgs Sector and One Extra Singlet

The paper presents an overview of search results for dark matter (DM) candidate particles in DM scalar portal models at the Large Hadron Collider. Calculations of cross sections of DM particle production are presented for the process of associated DM production with a gauge Z0 boson in a model with a two-doublet Higgs sector containing an additional scalar or pseudoscalar. It is shown that when analyzing the data of proton–proton collisions at an energy in the center-of-mass system of 13 TeV with a corresponding integrated luminosity of 137 fb−1, collected by CMS experiment at the LHC in 2016–2018, no significant excess of the expected signal over the background predicted by the standard model is observed. Constraints on the parameter space of (2HDM+a) scalar portal model obtained by CMS during the LHC second run (Run 2) and prospects for the third run are discussed.