WHAT E+E- COLLIDER COULD MAKE A NO-LOSE SEARCH FOR MINIMAL SUPERSYMMETRIC STANDARD MODEL HIGGS BOSONS

The lightest CP-even Higgs boson h in the minimal supersymmetric standard model (MSSM) has a mass upper bound depending on the top quark and squark masses. An e+e- collider with enough energy and luminosity to produce h + Z at measurable rates up to the maximum h mass would cover the entire MSSM parameter space if h + A production was also searched for. We explore the energy and/or luminosity needed for various top quark and squark masses. For m(t) = 150 GeV and a 1 TeV supersymmetric mass scale, a 230 GeV collider with 10 fb-1 luminosity would suffice, based on e+e- --> hZ, hA --> tautaujj signals. With future b tagging, other channels will contribute important additional signals and the luminosity requirements will be lowered by up to an order of magnitude.