Measurement of the tt¯Ztt¯Z and tt¯Wtt¯W production cross sections in multilepton final states using 3.2 fb−1−1 of pppp collisions at √s = 13 TeV with the ATLAS detector

Abstract

A measurement of the ttZ¯ and ttW¯ production cross sections in final states with either two same-charge muons, or three or four leptons (electrons or muons) is presented. The analysis uses a data sample of proton–proton collisions at √s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015, corresponding to a total integrated luminosity of 3.2 fb−1. The inclusive cross sections are extracted using likelihood fits to signal and control regions, resulting in σttZ¯ = 0.9 ± 0.3 pb and σttW¯ = 1.5 ± 0.8 pb, in agreement with the Standard Model predictions.