QCD NLO and EW NLO corrections to $t\bar{t}H$ production with top quark decays at hadron collider

Abstract

Higgs boson production associated with a top quark pair is an important process in studying the nature of the newly discovered Higgs boson at the LHC. In this letter, we report on our calculations including the next-to-leading order (NLO) QCD and NLO electroweak corrections to the $pp\to t\bar{t}H$ process in the standard model. We present the integrated cross sections at the $14~{\rm TeV}$ LHC and even at the future proton-proton colliders with $\sqrt{s}=33$ and $100~{\rm TeV}$. Our calculation includes the top quark subsequent decays by adopting the narrow width approximation. The kinematic distributions of Higgs boson and top quark decay products at the LHC are provided. We find that the ${\cal O}(α_s^2α_{ew}^2)$ corrections are quantitatively comparable with the ${\cal O}(α_s^3α_{ew})$ corrections in some kinematic region.

Figures (6)

• Figure 1: The box (upper row) and pentagon diagrams (the lower two rows) for $q\bar{q}\to t\bar{t} H$ subprocess containing a gluon in loop, where $V=Z,\gamma$. For box diagrams, the graphs with a Higgs boson radiated off the external anti-top are not drawn. For pentagon diagrams, the graphs by exchanging the initial quark and anti-quark are not drawn.
• Figure 2: Some representative tree-level diagrams for gluon bremsstrahlung subprocess $q\bar{q}\to t\bar{t} H+g$ at the ${\cal O}(\alpha_s^{3/2} \alpha_{ew}^{1/2})$ (upper row) and ${\cal O}(\alpha_s^{1/2} \alpha_{ew}^{3/2})$ (lower row, where $V=Z,\gamma$).
• Figure 3: (a) The LO, NLO QCD, NLO EW corrected distributions of the transverse momenta of the lepton $l^+$ ($l^+ =e^+,\mu^+$) at the $14~{\rm TeV}$ LHC. The contributions from the $g\gamma \to t\bar{t}H$ subprocess are also shown there. (b) The corresponding relative corrections.
• Figure 4: (a) The LO, NLO QCD, NLO EW corrected distributions of the Higgs boson transverse momenta at the $14~{\rm TeV}$ LHC. The contributions from the $g\gamma \to t\bar{t}H$ subprocess are also shown there. (b) The corresponding relative corrections.
• Figure 5: (a) The LO, NLO QCD, NLO EW corrected distributions of lepton pair invariant mass ($l^+l^- =e^+e^-$, $e^+\mu^-$, $\mu^+e^-$, $\mu^+\mu^-$) at the $14~{\rm TeV}$ LHC. The contributions from the $g\gamma \to t\bar{t}H$ subprocess are also shown there. (b) The corresponding relative corrections.