Abstract

© 2016 The Author.The production of W±Z events in proton–proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC. The collected data correspond to an integrated luminosity of 3.2 fb−1. The W±Z candidates are reconstructed using leptonic decays of the gauge bosons into electrons or muons. The measured inclusive cross section in the detector fiducial region for leptonic decay modes is σfid.W±Z→ℓʹ νℓℓ=63.2 ±3.2 ±2.6 ±1.5 fb. In comparison, the next-to-leading-order Standard Model prediction is 53.4+3.6−2.8fb. The extrapolation of the measurement from the fiducial to the total phase space yields σtot.W±Z=50.6 ±2.6 ±2.0 ±0.9 ±1.2 pb, in agreement with a recent next-to-next-to-leading-order calculation of 48.2+1.1−1.0pb. The cross section as a function of jet multiplicity is also measured, together with the charge-dependent W+Z and W−Z cross sections and their ratio.