Next-to-leading order predictions for WW+jet production

128

176

We consider QCD radiative corrections to W + W − production at the LHC and present the first fully differential predictions for this process at next-to-next-to-leading order (NNLO) in perturbation theory. Our computation consistently includes the leptonic decays of the W bosons, taking into account spin correlations, off-shell effects and nonresonant contributions. Detailed predictions are presented for the different-flavour channel pp → µ + e − ν µνe + X at √ s = 8 and 13 TeV. In particular, we discuss fiducial cross sections and distributions in the presence of standard selection cuts used in experimental W + W − and H → W + W − analyses at the LHC. The inclusive W + W − cross section receives large NNLO corrections, and, due to the presence of a jet veto, typical fiducial cuts have a sizeable influence on the behaviour of the perturbative expansion. The availability of differential NNLO predictions, both for inclusive and fiducial observables, will play an important role in the rich physics programme that is based on precision studies of W + W − signatures at the LHC.

Section: Introductionmentioning

confidence: 99%

W + W − production at the LHC: fiducial cross sections and distributions in NNLO QCD

Grazzini

Kallweit

Pozzorini

et al. 2016

128

176

“…Analytic results for the one-loop calculation of the W + W − +3 parton process have been given in ref. [136]. After simple modifications these results can also be applied to the W Z and ZZ processes.…”

Section: Above Cut Contributionsmentioning

confidence: 99%

“…Although the results of ref. [136] were in analytic form, considerable effort has been devoted to simplifying these results [137]. Analytic results for the one-loop calculation of the W + γ+3 parton process, applicable also to the Zγ process, have been given in ref.…”

Section: Above Cut Contributionsmentioning

confidence: 99%

Non-local slicing approaches for NNLO QCD in MCFM

Campbell

Ellis

Seth

2022

Self Cite

We present the implementation of several processes at Next-to-Next-to Leading Order (NNLO) accuracy in QCD in the parton-level Monte Carlo program MCFM. The processes treated are pp → H, W±, Z, W±H, ZH, W±γ, Zγ and γγ and, for the first time in the code, W+W−, W±Z and ZZ. Decays of the unstable bosons are fully included, resulting in a flexible fully differential Monte Carlo code. The NNLO corrections have been calculated using two non-local slicing approaches, isolating the doubly unresolved region by cutting on the zero-jettiness, $$ \mathcal{T} $$ T 0, or on qT, the transverse momentum of the colour singlet final-state particles. We find that for most, but not all processes the qT slicing method leads to smaller power corrections for equal computational burden.

“…We note that results for this process, in the limit of massless quarks circulating in the loop, have been calculated in analytic form previously [28], but the resulting amplitudes were only distributed in the form of computer code since they were not sufficiently compact to present otherwise.…”

Section: Motivationmentioning

confidence: 99%

Vector boson pair production at one loop: analytic results for the process $$ \mathrm{q}\overline{\mathrm{q}}\ell \overline{\ell}{\ell}^{\prime }{\overline{\ell}}^{\prime}\mathrm{g} $$

Campbell

Laurentis

Ellis

2022

Self Cite

We present compact analytic results for the one-loop amplitude for the process 0 → $$ q\overline{q}\ell \overline{\ell}{\ell}^{\prime }{\overline{\ell}}^{\prime }g $$ q q ¯ ℓ ℓ ¯ ℓ ′ ℓ ¯ ′ g , relevant for both the production of a pair of Z and W-bosons in association with a jet. We focus on the gauge-invariant contribution mediated by a loop of quarks. We explicitly include all effects of the loop-quark mass m, appropriate for the production of a pair of Z-bosons. In the limit m → 0, our results are also applicable to the production of W-boson pairs, mediated by a loop of massless quarks. Implemented in a numerical code, the results are fast. The calculation uses novel advancements in spinor-helicity simplification techniques, for the first time applied beyond five-point massless kinematics. We make use of primary decompositions from algebraic-geometry, which now involve non-radical ideals, and p-adic numbers from number theory. We show how to infer whether numerator polynomials belong to symbolic powers of non-radical ideals through numerical evaluations.