Supersymmetry reach of Fermilab Tevatron upgrades: The large tanthinsp{beta} case

The Yukawa couplings of the tau lepton and the bottom quark become comparable to, or even exceed, electroweak gauge couplings for large values of the supersymmetry parameter tanthinsp{beta}. As a result, the lightest tau slepton {tilde {tau}}{sub 1} and bottom squark {tilde b}{sub 1} can be significantly lighter than corresponding sleptons and squarks of the first two generations. Gluino, chargino, and neutralino decays to third generation particles are significantly enhanced when tanthinsp{beta} is large. This affects projections for collider experiment reach for supersymmetric particles. In this paper, we evaluate the reach of the Fermilab Tevatron p{bar p} collider for supersymmetric signals in the framework of the minimal supergravity model. We find that the reach via signatures with multiple isolated leptons ({ital e} and {mu}) is considerably reduced. For very large tanthinsp{beta}, the greatest reach is attained in the multijet+E{sub T}{sup miss} signature. Some significant extra regions may be probed by requiring the presence of an identified {ital b} jet in jets+E{sub T}{sup miss} events, or by requiring one of the identified leptons in clean trilepton events to actually be a hadronic 1 or 3 charged prong tau. In an appendix, we present formulas for chargino, neutralino, and gluino three bodymore » decays which are valid at large tanthinsp{beta}. {copyright} {ital 1998} {ital The American Physical Society}« less