The WZ production cross section is measured in proton-proton collisions at a centre-of-mass energy $\sqrt{ s} =$ 13 TeV using data collected with the CMS detector, corresponding to an integrated luminosity of 35.9 fb$^{ -1}$. The inclusive cross section is measured to be $\sigma_{ \text{ tot}}$(pp $\to$ WZ$)$ = 48.09 $^{ +1.00}_{ -0.96}$ (stat) $^{ +0.44}_{ -0.37}$ (theo) $^{ +2.39}_{ -2.17}$ (syst) $\pm$ 1.39 (lumi) pb, resulting in a total uncertainty of $-$2.78/$+$2.98 pb. Fiducial cross section and ratios of charge-dependent cross section measurements are provided. Differential cross section measurements are also presented with respect to three variables: the Z boson transverse momentum $p_\mathrm{ T}$, the leading jet $p_\mathrm{ T}$, and the $m$(WZ) variable, defined as the invariant mass of the system composed of the three leptons and the missing transverse momentum. Differential measurements with respect to the W boson $p_\mathrm{ T}$, separated by charge, are also shown. Results are consistent with standard model predictions, favouring next-to-next-to-leading-order predictions over those at next-to-leading order. Constraints on anomalous triple gauge couplings are derived via a binned maximum likelihood fit to the $m$(WZ) variable.
Categories: hep-ex