Beyond the Higgs boson at the Tevatron: Detecting gluinos from Yukawa-unified SUSY

Simple SUSY GUT models based on the gauge group SO(10) require t-b-tau Yukawa coupling unification, in addition to gauge coupling and matter unification. The Yukawa Coupling unification places strong constraints on the expected superparticle mass spectrum, with scalar masses similar to 10 TeV while gluino masses are Much lighter: in the 300-500 GeV range. The very heavy squarks Suppress negative interference in the q (q) over bar -> (g) over bar(g) over bar cross section, leading to a large enhancement in production rates. The gluinos decay almost always via three-body modes into a pair of b-quarks, so we expect at least four b-jets per signal event. We investigate the capability of Fermilab Tevatron collider experiments to detect gluino pair production in Yukawa-unified SUSY. By requiring events with large missing E-T and >= 2 or 3 tagged b-jets, we find a 5 sigma reach in excess of m((g) over bar) similar to 400 GeV for 5 fb(-1) of data. This range in m((g) over bar) is much further than the conventional Tevatron SUSY reach, and should cut a significant swath through the most favored region of parameter space for Yukawa-unified SUSY models. (C) 2010 Elsevier B.V. All rights reserved.