Heavy-Higgs-boson resonance

We study the use of the standard Higgs boson, with ${\mathit{m}}_{\mathit{H}}$>700 GeV, as a model for a resonance in longitudinal-vector-boson scattering. We focus on the constraint placed upon the modulus of the amplitude by unitarity. We show that it is better to use the energy-dependent width Γ(s)=${\mathrm{\Gamma }}_{\mathit{H}}$×(s/${\mathit{m}}_{\mathit{H}}^2$ ${)}^2$ in the Higgs-boson propagator, rather than the usual approximation Γ(s)=${\mathrm{\Gamma }}_{\mathit{H}}$. The s-channel approximation, the effective-W approximation, and the full electroweak qq→qqVV process are discussed.