COMPLETE TREE-LEVEL CALCULATION OF THE REACTION E(-)-]MU(+)MU(-)B(B)OVER-BAR AND THE HIGGS-BOSON SIGNAL AT LEP200 AND NLC ENERGIES()E()

A complete tree-level calculation of the reaction e+e- --> mu+mu-bbBAR in the electroweak standard theory for the energy range of LEP200 and the next linear collider is presented. The matrix elements have been calculated by employing the computer program CompHEP, the phase space integrals by the Monte Carlo integrator and event generator BASES/SPRI NG. The dependence of the 4-fermion cross section on energy and the Hi ggs boson mass is studied in detail. Interference contributions betwee n the various diagrams are found not to alter significantly the produc tion and decay properties of the Higgs boson. It is shown that already the counting rate of the reaction e+e- --> mu+mu- bbBAR at LEP 200 ca n provide evidence for the existence of the Higgs boson.