Probing NLSP Top Squark from Heavy Gluino at the LHC

TL;DR

This paper investigates the discovery potential of heavy gluinos at the LHC through same-sign dilepton signatures, providing updated mass bounds and discovery limits at 7, 8, and 14 TeV energies for various stop decay scenarios.

Contribution

It offers new analysis of gluino discovery limits at different LHC energies considering specific stop decay channels and simplified spectra, extending previous bounds.

Findings

7 TeV LHC sets ~800 GeV gluino lower bound.

8 TeV LHC can reach up to 1.2 TeV gluino mass.

14 TeV LHC can discover gluinos up to 1.9 TeV.

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\tilde{\chi}_1^0, bW^+\tilde{\chi}_1^0 or t\tilde{\chi}_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\tilde{\chi}_1^0, bW^+\tilde{\chi}_1^0 and t\tilde{\chi}_1^0 respectively, corresponding to 3 (5) \sigma significance. 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.