W ±Z production at NNLO QCD and NLO EW matched to parton showers with MiNNLOPS

Abstract

We consider W±Z production in hadronic collisions and present high-precision predictions in QCD and electroweak (EW) perturbation theory matched to parton showers. To this end, we match next-to-next-to-leading order QCD corrections to parton showers using the MiNNLOPS method and consistently combine them with next-to-leading order EW corrections matched to parton showers. This is the first time such accuracy in the event generation is achieved for any collider process, and we study in detail the impact of different choices in the combination of QCD and EW corrections as well as QCD and QED showers. Spin correlations, interferences and off-shell effects are retained by considering the full leptonic processes $$ pp\to {\ell}^{+}{\ell}^{-}{\ell}^{\prime \pm }{\nu}_{\ell}^{\prime } $$ pp → ℓ + ℓ − ℓ ′ ± ν ℓ ′ with ℓ′ ≠ ℓ and ℓ′ = ℓ without approximations, and the matching to QED radiation is performed preserving the resonance structure of the process. We find that NNLO QCD predictions including QCD and QED shower effects provide a very good approximation in the bulk-region of the phase space, while EW effects become increasingly important in the high-energy tails of kinematic distributions. Our default predictions are in excellent agreement with recent ATLAS data.

NNLO+PS predictions for Higgs production through bottom-quark annihilation with MINNLO$$\varvec{_{\text {PS}}}$$

“…[48] and applied to several colour-singlet production processes in Refs. [48][49][50][51][52][53][54][55][56], it was even reformulated for the case of heavy quark-pair production [57][58][59], being the first method applicable to processes with colour charges in both initial and final state thus far.…”

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.…”

Combining NNLO QCD and NLO EW corrections matched to parton showers for $W^\pm Z$ production using $\mathrm{MiNNLO}_\mathrm{PS}$

“…The usual Powheg B function is modified into B MiNNLO PS to reach NNLO accuracy. Symbolically, it reads B MiNNLO PS = 𝑒 −𝑆 d𝜎 (1) FJ dΦ FJ 1 + 𝑆 (1) + d𝜎 (2) FJ dΦ FJ + 𝐷 − 𝐷 (1) − 𝐷 (2) × 𝐹 corr ,…”

“…As for now, no clear hints of physics beyond the Standard Model (SM) have been observed and precision can serve as a valuable tool for detecting a deviation in the data/theory comparison. In this proceeding, we will review a method to consistently combine next-to-next-to-leading order (NNLO) QCD computations and next-to-leading order (NLO) EW corrections matched to parton showers, as originally presented in [1].…”

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We present results for 𝑊 ± 𝑍 production at NNLO QCD and NLO electroweak (EW) accuracy matched to parton showers [1]. NNLO QCD corrections matched to parton showers are obtained through the MiNNLO PS method, while NLO EW results matched to parton showers are produced using the POWHEG approach.

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