Bounds on the Ratio of Higgs Vacuum Expectation Values in the Minimal Supersymmetric Standard Model from the Top and Bottom Quark Masses

Abstract

The top quark mass values from the CDF Collaboration and the precision electroweak data at LEP combined with the bottom mass value allow to establish bounds on the parameter tan beta in the minimal supersymmetric standard model (MSSM) independent of the soft supersymmetry breaking parameters. We find: 0.96 < tan beta < 52.2 at the 95 % C.L., which is mostly the region tan beta >1, where radiative electroweak symmetry breaking is possible. Assuming electroweak symmetry breaking leads to: tan beta=1.2 +- 0.2, if one neglects the high tan beta solution, which is unlikely due to proton lifetime limits.