Results from a wide range of searches targeting different experimental signatures with and without missing transverse momentum ($E_{ \mathrm{ T}}^{ \mathrm{ miss}}$) are used to constrain a Two-Higgs-Doublet Model (2HDM) with an additional pseudo-scalar mediating the interaction between ordinary and dark matter (2HDM+$a$). The analyses use up to 139 fb$^{ -1}$ of proton-proton collision data at a centre-of-mass energy $\sqrt{ s}=13$ TeV recorded with the ATLAS detector at the Large Hadron Collider during 2015-2018. The results from three of the most sensitive searches are combined statistically. These searches target signatures with large $E_{ \mathrm{ T}}^{ \mathrm{ miss}}$ and a leptonically decaying $Z$ boson; large $E_{ \mathrm{ T}}^{ \mathrm{ miss}}$ and a Higgs boson decaying to bottom quarks; and production of charged Higgs bosons in final states with top and bottom quarks, respectively. Constraints are derived for several common and new benchmark scenarios in the 2HDM+$a$.
Categories: hep-ex