Next-to-next-to-leading order event generation for VH production with H → $$ b\overline{b} $$ decay

Abstract

We consider the Higgsstrahlung process in hadronic collisions and present the computation of next-to-next-to-leading order predictions matched to parton showers for both production and H → $$ b\overline{b} $$ b b ¯ decay employing the MiNNLOPS method. We present predictions for ZH and W±H production including spin correlations and off-shell effects by calculating the full processes pp → ℓ+ℓ−H → ℓ+ℓ−$$ b\overline{b} $$ b b ¯ , pp → $$ {\nu}_{\ell }{\overline{\nu}}_{\ell }H $$ ν ℓ ν ¯ ℓ H → $$ {\nu}_{\ell }{\overline{\nu}}_{\ell }b\overline{b} $$ ν ℓ ν ¯ ℓ b b ¯ and pp → ℓ±νℓH → $$ {\ell}^{\pm }{\overline{\nu}}_{\ell }b\overline{b} $$ ℓ ± ν ¯ ℓ b b ¯ in the narrow-width approximation for the Higgs boson. For the W±H process, NNLO+PS accuracy in production and decay is achieved for the first time. Our calculations are validated against earlier simulations in the NNLOPS approach that includes NNLO corrections via multi-differential reweighting. The new MiNNLOPS generators for these processes, which evaluate NNLO corrections on-the-fly in the event generation, will supersede those earlier calculations. Our predictions are in good agreement with recent measurements of the Higgsstrahlung cross sections.

On the NLO QCD corrections to gluon-initiated ZH production

“…[30] and a numerical evaluation using sector decomposition [31]. All of the previous results show that the NLO corrections are comparable in magnitude to the LO contribution, 2 and this fact makes the implementation of the NLO terms in a Monte Carlo code (possibly interfaced with parton-shower generators [32,33]) a priority for a reliable interpretation of the experimental results. 3 In this paper we take a step towards this goal, as we provide a fast and flexible way to compute gg → ZH at NLO in QCD including the effects of a finite top-quark mass.…”

Infrared-safe flavoured anti-kT jets

“…sensible results to all orders is a well-motivated strategy. Similarly, although cross section predictions including resummation of multi-parton emissions do not require the use of a flavour-aware jet algorithm, several studies made use of the flavoured k T algorithm in the context of parton showers [21][22][23][24] and analytic resummation [25,26].…”

B-hadron production at the LHC from bottom-quark pair production at NNLO+PS

“…Leading-order (LO) Feynman diagrams for this process are shown in Figure 1. Our calculation is based on the MiNNLO PS method [53,54], which was originally developed and later used for several colour-singlet processes [55][56][57][58][59][60][61][62]. More precisely, we employ the extension of the MiNNLO PS method that was derived and applied to top-quark pair production in Refs.…”