Search for Dark Matter with 2HDM+a in pp Collisions at $$\sqrt {s}$$ = 13 TeV with the ATLAS Detector

Abstract Results obtained from various searches with and without missing transverse energy are used to constrain a Two-Higgs-Doublet Model with an additional pseudo-scalar. The analysis utilizes data from proton-proton collisions recorded with the ATLAS experiment at the LHC during 2015 and 2018 at a center-of-mass energy of $$\sqrt {s} = 13$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mrow> <mml:mi>s</mml:mi> </mml:mrow> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:math> TeV, corresponding to an integrated luminosity of 139 $$\text{fb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mtext>fb</mml:mtext> </mml:mrow> <mml:mrow> <mml:mn>−1</mml:mn> </mml:mrow> </mml:msup> </mml:math> . This paper highlights the results from the statistical combination of three highly sensitive searches.