Measurement of W±and Z-boson production cross sections in ppcollisions at √s=13TeVwith the ATLAS detector

Abstract

Measurements of the W±→ ±νand Z→ + −production cross sections (where ±=e±, μ±) in proton–proton collisions at √s=13TeVare presented using data recorded by the ATLAS experiment at the Large Hadron Collider, corresponding to a total integrated luminosity of 81pb−1. The total inclusive W±-boson production cross sections times the single-lepton-flavour branching ratios are σtotW+=11.83 ±0.02(stat)±0.32(sys)±0.25(lumi)nband σtotW−=8.79 ±0.02(stat)±0.24(sys)±0.18(lumi)nbfor W+and W−, respectively. The total inclusive Z-boson production cross section times leptonic branching ratio, within the invariant mass window 66 <m <116GeV, is σtotZ=1.981 ±0.007(stat)±0.038(sys)±0.042(lumi)nb. The W+, W−, and Z-boson production cross sections and cross-section ratios within a fiducial region defined by the detector acceptance are also measured. The cross-section ratios benefit from significant cancellation of experimental uncertainties, resulting in σfidW+/σfidW−=1.295 ±0.003(stat)±0.010(sys)and σfidW±/σfidZ=10.31 ±0.04(stat)±0.20(sys). Theoretical predictions, based on calculations accurate to next-to-next-to-leading order for quantum chromodynamics and to next-to-leading order for electroweak processes and which employ different parton distribution function sets, are compared to these measurements.