Search for supersymmetry in events with b-tagged jets and missing transverse momentum in pp collisions at vs = 13 TeV with the ATLAS detector

A search for the supersymmetric partners of the Standard Model bottom and top quarks is presented. The search uses 36.1 fb-1 of pp collision data at vs = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Direct production of pairs of bottom and top squarks (b˜1 and t˜1) is searched for in final states with b-tagged jets and missing transverse momentum. Distinctive selections are defined with either no charged leptons (electrons or muons) in the final state, or one charged lepton. The zero-lepton selection targets models in which the b˜1 is the lightest squark and decays via b˜1 ? b?˜01 , where ˜?01 is the lightest neutralino. The one-lepton final state targets models where bottom or top squarks are produced and can decay into multiple channels, b˜1 ? b?˜01 and b˜1 ? t?˜±1, or t˜1 ? t?˜01 and t˜1? b?˜±1, where ˜?±1 is the lightest chargino and the mass difference m?˜±1 - m?˜01 is set to 1 GeV. No excess above the expected Standard Model background is observed. Exclusion limits at 95% confidence level on the mass of third-generation squarks are derived in various supersymmetry-inspired simplified models.