Determining $tan \beta$ from the SUSY Higgs Sector at Future e^+e^-   Colliders
  We examine the prospects for determining $tan \beta$ from heavy Higgs scalar production in the minimal supersymmetric standard model at a future $e^+ e^-$ collider. Our analysis is independent of assumptions of parameter unification, and we consider general radiative corrections in the Higgs sector. Bounds are presented for $\sqrt{s} = 500$ GeV and 1 TeV, several Higgs masses, a variety of integrated luminosities and b-tagging efficiencies, and in scenarios with and without supersymmetric decays of the Higgs bosons. We find stringent constraints for $3 \alt tan \beta \alt 10$, and, for some scenarios, also interesting bounds on high $tan \beta$ through $tbH^{\pm}$ production. These bounds imply that simple Yukawa unifications may be confirmed or excluded. Implications for soft scalar mass determination and top squark parameters are also discussed. 
Jonathan L. Feng and Takeo Moroi