Testing supergravity grand unification at future accelerator and underground experiments.

Abstract

The full parameter space of supergravity grand unified theory with SU(5)-type $p\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}K$ proton decay is analyzed using renormalization-group-induced electroweak symmetry breaking under the restrictions that the universal scalar mass ${m}_{0}$ and gluino mass are \ensuremath{\le}1 TeV (no extreme fine tuning) and the Higgs triplet mass obeys $\frac{{M}_{{H}_{3}}}{{M}_{G}l10}$. Future proton decay experiments at SuperKamiokande or ICARUS can reach a sensitivity for the $\overline{\ensuremath{\nu}}K$ mode of (2-5)\ifmmode\times\else\texttimes\fi{}${10}^{33}$ yr allowing a number of predictions concerning the SUSY mass spectrum. Thus either the $p\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}K$ decay mode will be seen at these experiments or a chargino of mass ${m}_{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{W}}l100$ GeV will exist and hence be observable at CERN LEP2. Further, if $(p\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}K)g1.5\ifmmode\times\else\texttimes\fi{}{10}^{33}$ yr, then either the light Higgs boson has mass ${m}_{h}\ensuremath{\le}95$ GeV or ${m}_{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{W}}\ensuremath{\le}100$ GeV, i.e., either the light Higgs boson or the light chargino (or both) would be observable at LEP2. Thus, the combination of future accelerator and future underground experiments allow for strong experimental tests of this theory.