Search for bottom-squark pair production with the ATLAS detector in final states containing Higgs bosons, b-jets and missing transverse momentum

Abstract

The result of a search for the pair production of the lightest supersymmetric partner of the bottom quark (~b1) using 139 fb􀀀1 of proton-proton data collected at p s = 13TeV by the ATLAS detector is reported. In the supersymmetric scenarios considered both of the bottom-squarks decay into a b-quark and the second-lightest neutralino, ~b1 ! b + ~ 02 . Each ~ 02 is assumed to subsequently decay with 100% branching ratio into a Higgs boson (h) like the one in the Standard Model and the lightest neutralino: ~ 02 ! h + ~ 01 . The ~ 01 is assumed to be the lightest supersymmetric particle (LSP) and is stable. Two signal mass con gurations are targeted: the rst has a constant LSP mass of 60 GeV; and the second has a constant mass di erence between the ~ 02 and ~ 01 of 130 GeV. The nal states considered contain no charged leptons, three or more b-jets, and large missing transverse momentum. No signi cant excess of events over the Standard Model background expectation is observed in any of the signal regions considered. Limits at the 95% con dence level are placed in the supersymmetric models considered, and bottom-squarks with mass up to 1.5TeV are excluded.