Search for Super Symmetry in Events with B-Tagged Jets and Missing Transverse Momentum in pp Collisions at √s=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 √s = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Direct production of pairs of bottom and top squarks (b̅₁ and t̅₁) 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 b̅₁ is the lightest squark and decays via (b̅₁ → bχ̅₁⁰, where χ̅₁⁰ is the lightest neutralino. The one-lepton final state targets models where bottom or top squarks are produced and can decay into multiple channels, b̅₁ → bχ̅₁⁰ and b̅₁ → tχ̅₁(±), or t̅₁ → tχ̅₁⁰ and t̅₁ → bχ̅₁(±), where χ̅₁⁰(±) is the lightest chargino and the mass difference m(χ̅₁(±)) - m(χ̅₁⁰) 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.