Observation of electroweak W ± Z boson pair production in association with two jets in pp collisions at √ s = 13 TeV with the ATLAS detector

Article history: Received 27 December 2018 Received in revised form 16 April 2019 Accepted 6 May 2019 Available online 13 May 2019 Editor: M. Doser An observation of electroweak W ± Z production in association with two jets in proton–proton collisions is presented. The data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016 at a centre-of-mass energy of √ s = 13 TeV are used, corresponding to an integrated luminosity of 36.1 fb−1. Events containing three identified leptons, either electrons or muons, and two jets are selected. The electroweak production of W ± Z bosons in association with two jets is measured with an observed significance of 5.3 standard deviations. A fiducial cross-section for electroweak production including interference effects and for a single leptonic decay mode is measured to be σW Z jj−EW = 0.57 +0.14 −0.13 (stat.) +0.07 −0.06 (syst.) fb. Total and differential fiducial cross-sections of the sum of W ± Z j j electroweak and strong productions for several kinematic observables are also measured. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.