Heavy-Quark Associated Production with One Hard Photon at Hadron Colliders

We present the calculation of heavy-quark associated production with a hard photon at hadron colliders, namely pp(p pbar) -> Q Qbar gamma +X (for Q = t, b), at Next-to-Leading Order (NLO) in Quantum Chromodynamics (QCD). We study the impact of NLO QCD corrections on the total cross section and several differential distributions at both the Tevatron and the Large Hadron Collider (LHC). For t tbar gamma production we observe a sizeable reduction of the renormalization and factorization scale dependence when the NLO QCD corrections are included, while for b bbar gamma production a considerable scale dependence still persists at NLO in QCD. This is consistent with what emerges in similar processes involving b quarks and vector bosons and we explain its origin in detail. For b bbar gamma production we study both the case in which at least one b jet and the case in which at least two b jets are observed. We perform the b bbar gamma calculation using the Four Flavor Number Scheme (4FNS) and compare the case where at least one b jet is observed with the corresponding results from the Five Flavor Number Scheme (5FNS) calculation. Finally we compare our results for p pbar -> gamma + b + X with Tevatron data.