Search for heavy Higgs signals at hadronic supercolliders

The purpose of this thesis is to formulate strategies to search for a heavy Higgs-boson signal or a strongly-interacting symmetry-breaking sector, by studying the scattering of longitudinal weak-boson pairs (W+W+, ZZ, W+W- and WZ) at future pp supercolliders. The central issue is how to extract the longitudinal boson scattering contributions, so that the strongly interacting symmetry-breaking effects can be isolated. The W+LW+L scattering contributions to pp → W+LW+LX at the SSC and LHC are calculated, that have been proposed as probes of possible strong interactions in the electroweak symmetry-breaking sector. A central jet-vetoing technique is developed to extract the WLWL scattering from non-scattering contributions. Next a comparative study is made of jet-inclusive and single jet-tagging, the signal/background ratio and significance of the signal are improved. Another viable channel for discovery of a heavy Higgs-boson is the leptonic decay mode of H → W+W- → ell + ν ell -ν. By the single jet-tagging technique and central jet-vetoing the heavy Higgs-boson signal in this channel can be separated from the SM backgrounds, including QCD production of WW pair with jets, and t anti t production with each t → bW. For WZ channel, a full tree-level calculation of qq → qqWZ is made, which is the first to appear in literature. The QCD backgrounds to WZ pair production are also quantified. Any excessive production of WZ pairs above SM predictions will imply new physics