Phenomenological Implications of the $m_t$ RGE Fixed Point for SUSY Higgs Boson Searches

Abstract

In minimal SUSY-GUT models with $M_{SUSY}\text{ltap}1$ TeV, the renormalization group equations have a solution dominated by the infrared fixed point of the top Yukawa coupling. This fixed point predicts $m_t=(200\mathrm{GeV})\sin \beta$; combined with the LEP results it excludes $m_t\text{ltap}130$ GeV. For $m_t$ in the range 130-160 GeV, we discuss the sensitivity of the $m_t$ fixed point result to GUT threshold corrections and point out the implications for Higgs boson searches. The lightest scalar $h$ has mass 60-85 GeV and will be detectable at LEPII. At SSC/LHC, each of the five scalars $h$, $H$, $A$, $H^{\pm }$ may be detectable, but not all of them together; in one parameter region none will be detectable.

Comments: 12 pages + 4 PS figures not included (available upon request), MAD/PH/755