High Energy Seminar
Speaker: Walter Hopkins
Title: Direct Stop Searches at ATLAS
Host:
Room: 285
Abstract:
Supersymmetry (SUSY) is an extension of the Standard Model that can resolve the gauge hierarchy problem. The SUSY partner to the top quark(stop) plays an important role in canceling the dominant top quark loop diagram contributions to the divergence of the Higgs boson mass. The recent increase of center-of-mass energy of the LHC from 8 TeV to 13 TeV greatly extends the mass reach for SUSY searches. A summary of the searches for direct stop production, highlighting the zero-lepton channel analysis using 13.3 $fb^{-1}$ of $\sqrt{s}=13$ TeV data collected with the ATLAS experiment at the LHC. One of the stop decay modes considered is the decay to a top and a neutral lightest supersymmetric particle (LSP) resulting in signature with jets and large missing energy. No significant excess is observed above the background expectation in the stop signal regions and limits are set on the stop and LSP masses. Additional signal regions are designed and interpreted for DM+ttbar production. Finally, the outlook for stop searches for the remainder of Run 2 will be discussed.