Top-squark in natural SUSY under current LHC run-2 data

Abstract

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We utilize the recent LHC-13 TeV data to study the lower mass bound on the top-squark (stop) in natural supersymmetry. We recast the LHC sparticle inclusive search of [InlineEquation not available: see fulltext.]1)[InlineEquation not available: see fulltext.] with ...... variable, the direct stop pair search (1-lepton channel and all-hadronic channel) and the monojet analyses. We find that these searches are complementary depending on stop and higgsino masses: for a heavy stop the all-hadronic stop pair search provides the strongest bound, for an intermediate stop the inclusive SUSY analysis with ...... variable is most efficient, while for a compressed stop-higgsino scenario the monojet search plays the key role. Finally, the lower mass bound on a stop is: (1) 320 GeV for compressed stop-higgsino scenario (mass splitting less than 20 GeV); (2) 765 (860) GeV for higgsinos lighter than 300 (100) GeV.