tan{beta} determination from heavy Higgs boson production at linear colliders

We study the production at future e{sup +}e{sup -} linear colliders of the heavy neutral Higgs bosons H and A of the minimal supersymmetric standard model in association with top and bottom quarks. The cross sections have a strong dependence on the parameter tan{beta}, and thus provide a good way to determine it. At a linear collider with s=0.5--1 TeV and expected integrated luminosities, we find significant sensitivities for determining tan{beta}. In the supergravity scenario, the sensitivity is particularly strong for tan{beta}{approx}>10, reaching a 15% or better measurement. In the general MSSM scenario, the interplay between the 4b and 4t channels results in a good determination for tan{beta}{approx}<10, while the sensitivity is weakened for higher values of tan{beta}.