Higgs boson production with heavy quarks at hadron colliders

One of the remaining puzzles in particle physics is the origin of electroweak symmetry breaking. In the Standard Model (SM), a single doublet of complex scalar fields is responsible for breaking the SU(2) L x U(1)Y gauge symmetry thus giving mass to the electroweak gauge bosons via the Higgs mechanism and to the fermions via Yukawa couplings. The remnant of the process is a vet to he discovered scalar particle, the Higgs boson (h). However, current and future experiments at hadron colliders hold great promise.; Of particular interest at hadron colliders is the production of a Higgs boson in association with a pair of heavy quarks, pp¯(pp) → QQ¯h, where Q can be either a top or a bottom quark. Indeed, the production of a Higgs boson with a pair of top quarks provides a very distinctive signal in hadronic collisions where background processes are formidable, and it will be instrumental in the discovery of a Higgs boson below about 130 GeV at the LHC. On the other hand, the production of a Higgs boson with bottom quarks can be strongly enhanced in models of new physics beyond the SM, e.g. supersymmetric models. If this is the case, bb¯h production will play a crucial role at the Tevatron where it could provide the first signal of new physics.; Given the prominent role that Higgs production with heavy quarks can play at hadron colliders, it becomes imperative to have precise theoretical predictions for total and differential cross sections. In this dissertation, we outline and present detailed results for the next-to-leading order (NLO) calculation of the Quantum Chromodynamic (QCD) corrections to QQ¯h production at both the Tevatron and the LHC. This calculation involves several difficult issues due to the three massive particles in the final state, a situation which is at the frontier of radiative correction calculations in quantum field theory. We detail the novel techniques developed to deal with these challenges.; The calculation of pp¯(pp) → bb¯h at NLO in QCD involves several subtle issues not encountered in the case of pp¯(pp) → tt¯h. Recently, two different calculational schemes have been applied to the calculation of higher-order QCD corrections to bb¯h production. Here we compare these two seemingly different schemes and show that they produce compatible results for the total and differential cross sections in the cases of Higgs production with zero tagged b jets and one tagged b jet.