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

Abstract

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 (¯b₁ and ¯t₁) is searched for in nal states with b-tagged jets and missing transverse momentum. Distinctive selections are de ned with either no charged leptons (electrons or muons) in the nal state, or one charged lepton. The zero-lepton selection targets models in which the ¯b₁ is the lightest squark and decays via ¯b₁→b¯X⁰₁, where ¯X⁰₁ is the lightest neutralino. The one-lepton nal state targets models where bottom or top squarks are produced and can decay into multiple channels, ¯b₁→b¯X⁰₁ and ¯b₁→ t¯X^±₁, or ¯t₁ → t¯X⁰₁ and ¯t₁ → b¯X^±₁ , where ¯X^±₁ is the lightest chargino and the mass difference m_¯X^±₁ - m_¯X⁰₁ is set to 1 GeV. No excess above the expected Standard Model background is observed. Exclusion limits at 95% con dence level on the mass of third-generation squarks are derived in various supersymmetry-inspired simpli ed models.