Implications on the Supersymmetric Higgs sector from Top quark decays at the Tevatron

Abstract

From the tau-lepton analysis of the charged Higgs decay of the top quark at the Tevatron, t -> H+ b -> tau+ nu_{tau} b, it is possible to set rather stringent bounds on the (tan(beta),M_{H+})-plane, if one assumes that H+ is a charged member of a generic two-Higgs-doublet model. However, if we consider the possibility that H+ is supersymmetric, then we find that the allowed region in the (tan(beta),M_{H+})-plane can be significantly modified by the MSSM quantum corrections. Throughout our analysis we correlate the top quark results with the limits imposed by radiative and semileptonic B-meson decays. Remarkably, one can envision situations in the MSSM parameter space where H+ completely eludes those bounds, i.e. a charged Higgs with a mass below the top quark mass could coexist with essentially any value of tan(beta).