Measurement of the <i>t</i>(<i>t</i>)over-bar<i>Z</i> and <i>t</i>(<i>t</i>)over-bar<i>W</i> cross sections in proton-proton collisions at √<i>s</i>=13 TeV with the ATLAS detector



Aaboud, M, Aad, G, Abbott, B, Abbott, DC, Abdinov, O, Abeloos, B, Abhayasinghe, DK, Abidi, SH, AbouZeid, OS, Abraham, NL
et al (show 2924 more authors) (2019) Measurement of the <i>t</i>(<i>t</i>)over-bar<i>Z</i> and <i>t</i>(<i>t</i>)over-bar<i>W</i> cross sections in proton-proton collisions at √<i>s</i>=13 TeV with the ATLAS detector. PHYSICAL REVIEW D, 99 (7). pp. 1127-1133.

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Abstract

A measurement of the associated production of a top-quark pair ($t\bar{t}$) with a vector boson ($W$, $Z$) in proton-proton collisions at a center-of-mass energy of 13 TeV is presented, using $36.1$ fb$^{-1}$ of integrated luminosity collected by the ATLAS detector at the Large Hadron Collider. Events are selected in channels with two same- or opposite-sign leptons (electrons or muons), three leptons or four leptons, and each channel is further divided into multiple regions to maximize the sensitivity of the measurement. The $t\bar{t}Z$ and $t\bar{t}W$ production cross sections are simultaneously measured using a combined fit to all regions. The best-fit values of the production cross sections are $\sigma_{t\bar{t}Z} = 0.95 \pm 0.08_{\mathrm{stat.}} \pm 0.10_{\mathrm{syst.}}$ pb and $\sigma_{t\bar{t}W} = 0.87 \pm 0.13_{\mathrm{stat.}} \pm 0.14_{\mathrm{syst.}}$ pb in agreement with the Standard Model predictions. The measurement of the $t\bar{t}Z$ cross section is used to set constraints on effective field theory operators which modify the $t\bar{t}Z$ vertex.

Item Type: Article
Additional Information: 56 pages in total, author list starting page 40, 14 figures, 11 tables, published in Phys. Rev. D 99 (2019) 072009. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2016-11
Uncontrolled Keywords: hep-ex, hep-ex
Depositing User: Symplectic Admin
Date Deposited: 18 Feb 2019 17:36
Last Modified: 16 Mar 2024 00:59
DOI: 10.1103/PhysRevD.99.072009
Open Access URL: http://www.actaphys.uj.edu.pl/fulltext?series=Reg&...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3033062