Search for Dark Matter production associated with bottom quarks with 13.3 fb−1 of pp collisions at √s = 13 TeV with the ATLAS detector at the LHC

The result of a search for dark matter pair production in association with bottom quarks in 13.3 $fb^{-1}$ of $pp$ collisions collected at $\sqrt{s} = 13$ TeV by the ATLAS detector at the LHC is reported. The search is optimised for spin-0 mediators to the dark sector which are produced in association with bottom quarks and decay into a pair of Dirac Dark Matter particles. Events containing large missing transverse momentum and exactly two jets identified as originating from $b$-quarks are considered. The data are found to be consistent with the Standard Model background expectations. Limits at 95\% confidence level are derived on the production cross section of a spin-0 mediator decaying to a pair of Dark Matter particles and produced in association with $b$-quarks as a function of the mediator mass, assuming the Dark Matter particle mass to be 1~GeV.