Light Higgsinos, heavy gluino, and b-τ quasi-Yukawa unification: Prospects for finding the gluino at the LHC

摘要

A wide variety of unified models predict asymptotic relations at M_(GUT) between the b quark and τ lepton Yukawa couplings. Within the framework of supersymmetric SU(4) × SU(2)_L × SU(2)_R, we explore regions of the parameter space that are compatible with b-τ quasi Yukawa Unification, Higgsinos being the lightest supersymmetric particles (approx<1 TeV) accompanied by a relatively low level of fine-tuning determined by the parameter A_(EW)(approx<200). Among the colored sparticles, the stop weighs more than 1.5 TeV or so, whereas the squarks of the first two families are significantly heavier, approaching 10 TeV in some cases. The gluino mass is estimated to lie in the 2-4 TeV range which raises the important question: Will the LHC find the gluino?