학술논문
Measurements of the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson at s=13 TeV with the ATLAS detector
Document Type
Original Paper
Author
Source
The European Physical Journal C: Particles and Fields. 81(8)
Subject
Language
English
ISSN
1434-6044
1434-6052
1434-6052
Abstract
Measurements of both the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson (tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/) are presented. The measurements are performed by targeting final states with three or four isolated leptons (electrons or muons) and are based on tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/ TeV proton–proton collision data with an integrated luminosity of 139 tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/, recorded from 2015 to 2018 with the ATLAS detector at the CERN Large Hadron Collider. The inclusive cross section is measured to be tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/ (stat.) tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/ (syst.) pb, in agreement with the most precise theoretical predictions. The differential measurements are presented as a function of a number of kinematic variables which probe the kinematics of the tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/ system. Both absolute and normalised differential cross-section measurements are performed at particle and parton levels for specific fiducial volumes and are compared with theoretical predictions at different levels of precision, based on a tt¯Zs=13fb-1σtt¯Z=0.99±0.05±0.08tt¯Zχ2/ndf and p value computation. Overall, good agreement is observed between the unfolded data and the predictions.