QCD corrections to associated tt̄h production at the Fermilab Tevatron

We present in detail the calculation of the script O sign(α _s³) inclusive total cross section for the process pp̄→tt̄h in the Standard Model, at the Fermilab Tevatron center-of-mass energy √s_H=2 TeV. The next-to-leading order QCD corrections significantly reduce the renormalization and factorization scale dependence of the Born cross section. They slightly decrease or increase the Born cross section depending on the values of the renormalization and factorization scales.