On-Shell Methods Applied to Higgs Production with Heavy Quarks at NLO in QCD Physics

We calculate the production of a pair of heavy quarks ($Q\bar{Q}$) with a pseudoscalar ($A$) Higgs boson at hadron colliders, including NLO QCD corrections. The amplitude for $q\bar{q},gg\rightarrow Q\bar{Q} A$ is caculated both with a traditional Feynman-diagram approach and with more recently proposed on-shell methods. We use this process as a testing ground for the new on-shell methods in a case where several massive particles are involved.