Associated Production of a Top Quark and a Charged Higgs Boson

We compute the inclusive and differential cross sections for the associated production of a top quark along with a charged Higgs boson at hadron colliders to next-to-leading order in QCD and in supersymmetric QCD. For small Higgs boson masses we include the consistent treatment of resonant top quark pair production diagrams with a subsequent top quark decay into a bottom quark and a charged Higgs boson. We compare the NLO differential cross sections obtained in the bottom parton picture with the gluon-initiated process and observe remarkable consistency. The effects of supersymmetric loop contributions are systematically explored and only the corrections to the Yukawa coupling are sizable in the potential discovery region at the LHC. All expressions and numerical results are fully differential, permitting selections on the momenta of both the top quark and the charged Higgs boson.