Constricted SUSY from No-Scale ℱ-SU(5): A “blind spot” for LHC top quark reconstruction?

Abstract

We describe a region of the No-Scale supersymmetric model with TeV-scale vector-like matter multiplets that is potentially opaque to LHC observations based upon top quark reconstruction. Possessing a 100% on-shell branching fraction for gluino-to-light stop decays, the gluino-light stop mass splitting in lies very close to the top quark rest mass in the region . For unboosted gluino pair production, this could render two soft top quarks in the dominant 4-top signature, greatly reducing the likelihood for discrimination from the combinatoric background. We therefore suggest that caution is warranted when gluino exclusion bounds on models possessing a similar spectral character (gluino heavier than the light stop but lighter than all other squarks) using multijet SUSY search tactics. Alternate search methods are highlighted, including those based upon same-sign dileptons and multiple heavy flavor tags, which are more sensitive to this delicate kinematic “blind spot” crease.