Higgs Boson Production in Association with a Top-Antitop Quark Pair in Next-to-Next-to-Leading Order QCD

The associated production of a Higgs boson with a top-antitop quark pair is a crucial process at the LHC since it allows for a direct measurement of the top-quark Yukawa coupling. We present the computation of the radiative corrections to this process at the next-to-next-to-leading order (NNLO) in QCD perturbation theory. This is the very first computation for a 2 -> 3 process with massive colored particles at this perturbative order. We develop a soft Higgs boson approximation for loop amplitudes, which enables us to reliably quantify the impact of the yet unknown two-loop contribution. At the center-of-mass energy p 1/4 13 TeV, the NNLO corrections increase the next-to-leading order result for the total cross section by ffiffis about 4% and lead to a significant reduction of perturbative uncertainties.

Automated summary

The associated production of a Higgs boson with a top-antitop quark pair is a crucial process at the LHC, which allows for the measurement of the top-quark Yukawa coupling. The computation of radiative corrections to this process at NNLO in QCD perturbation theory is presented. This is the first computation for a 2 -> 3 process with massive colored particles at this perturbative order. A soft Higgs boson approximation for loop amplitudes is developed to quantify the impact of the unknown two-loop contribution. The NNLO corrections at a center-of-mass energy of 13 TeV increase the NLO result for the total cross section by about 4% and reduce perturbative uncertainties significantly.