Next-to-leading order QCD corrections to tZ associated production via the flavor-changing neutral-current couplings at hadron colliders

We present the complete next-to-leading order (NLO) QCD corrections to tZ associated production induced by the model-independent tqg and tqZ flavor-changing neutral-current couplings at hadron colliders, respectively. Our results show that, for the tuZ coupling the NLO QCD corrections can enhance the total cross sections by about 60% and 42%, and for the tcZ coupling by about 51% and 43% at the Tevatron and LHC, respectively. The NLO corrections, for the tug couplings, can enhance the total cross sections by about 27%, and by about 42% for the tcg coupling at the LHC. We also consider the mixing effects between the tqg and tqZ couplings for this process, which can either be large or small depending on the values of the anomalous couplings. Besides, the NLO corrections reduce the dependence of the total cross sections on the renormalization or factorization scale significantly, which lead to increased confidence on the theoretical predictions. And we also evaluate the NLO corrections to several important kinematic distributions.