$W^\pm Z$ production at the LHC: fiducial cross sections and distributions in NNLO QCD

We report on the first fully differential calculation for W$^{±}$ Z production in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. Leptonic decays of the W and Z bosons are consistently taken into account, i.e. we include all resonant and non-resonant diagrams that contribute to the process pp → ℓ$^{′}^{±}$ ν$_{ℓ}$ ′ ℓ$^{+}$ ℓ$^{−}$ +X both in the same-flavour (ℓ$^{′}$ = ℓ) and the different-flavour (ℓ$^{′}$ ≠ ℓ) channel. Fiducial cross sections and distributions are presented in the presence of standard selection cuts applied in the experimental W$^{±}$ Z analyses by ATLAS and CMS at centre-of-mass energies of 8 and 13 TeV. As previously shown for the inclusive cross section, NNLO corrections increase the NNLO result by about 10%, thereby leading to an improved agreement with experimental data. The importance of NNLO accurate predictions is also shown in the case of new-physics scenarios, where, especially in high-p$_{T}$ categories, their impact can reach $ \mathcal{O}\left(20\%\right) $ . The availability of differential NNLO predictions will play a crucial role in the rich physics programme that is based on precision studies of W$^{±}$ Z signatures at the LHC.