Next-to-leading order QCD predictions for tγ associated production via model-independent flavor-changing neutral-current couplings at hadron colliders

We present the complete next-to-leading order (NLO) QCD predictions for the tγ associated production induced by model-independent tqγ and tqg flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the tqγ and tqg FCNC couplings for this process. Our results show that, for the tqγ couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the tqγ, tqg FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the tuγ and tug FCNC couplings, and by about 80% for the tcγ and tcg FCNC couplings at the LHC, respectively. Moreover, the NLO corrections reduce the dependence of the total cross section on the renormalization and factorization scale significantly. We also evaluate the NLO corrections for several important kinematic distributions.