Techniques for the measurement of Higgs-boson branching fractions

We describe methods that can be employed at a [radical][ital s] =500 GeV [ital e][sup +][ital e[minus]] linear collider to measure the branching fractions of a Higgs boson. These methods select one Higgs-boson decay mode above all others with high purity, leaving measurable standard model backgrounds as the only source of contamination. Integrated luminosities of 50 fb[sup [minus]1] are required to obtain statistical error of 10--20 % on the branching fractions to [ital b[bar b]], [tau][sup +][tau][sup [minus]], and [ital WW][sup (*)]. For an intermediate-mass Higgs boson this is sufficient to distinguish the minimal supersymmetric standard model Higgs boson from the standard model Higgs boson over most of the supersymmetric parameter space.