Single and double Higgs production by gauge boson fusion

We investigate the fusion processes W+W- → Z0H0, W+W- → γH0 and W+W- → H0H0, where H0 denotes the standard model Higgs-boson. Calculations are performed for SSC energies using both the effective gauge boson treatment and the exact perturbative treatment of the constituent level processes qq → qq+Z0H0, etc. These approaches yield cross sections that are in reasonable agreement. The differences between the two are attributable to the additional diagrams present in the perturbative calculation due to gauge invariance. We study the differences as a function of rapidity and transverse momentum cuts. (orig.)