Probing NLSP Top Squark from Heavy Gluino at the LHC

Abstract

In this work we explore the 7 TeV LHC implication on light top squark (stop) and investigate discovery limits at both 8 and 14 TeV LHC using same-sign dilepton signature. We consider a simplified spectrum with gluino pair production followed by heavy gluino decay into on-shell stop and top quark in pair. The light stop is then assumed to uniquely decay into c\tildeχ_1^0, bW^+\tildeχ_1^0 or t\tildeχ_1^0. The same-sign dilepton search at 7 TeV LHC places a lower bound of about 800 GeV on the gluino mass in this scenario. We find that the 8 TeV LHC with 30 fb^{-1} luminosity can reach 960 (900) GeV, 1.2 (1.0) TeV and 1.3 (1.1) TeV of gluino mass for stop decay product of c\tildeχ_1^0, bW^+\tildeχ_1^0 and t\tildeχ_1^0 respectively, corresponding to 3 (5) σsignificance. The discovery limits of heavy gluino mass at the 14 TeV LHC with 100 fb^{-1} luminosity are 1.45 (1.35) TeV, 1.6 (1.55) TeV and 1.9 (1.68) TeV.

10 pages, 2 figures and 1 table. arXiv admin note: substantial text overlap with arXiv:1112.4461