Measurement of the $t\bar{t}$ production cross-section and lepton differential distributions in $eμ$ dilepton events from $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Collaboration, ATLAS (2020) Measurement of the $t\bar{t}$ production cross-section and lepton differential distributions in $eμ$ dilepton events from $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector. Eur. Phys. J. C, 80 (6). p. 528.

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Abstract

The inclusive top quark pair ($t\bar{t}$) production cross-section $\sigma_{t\bar{t}}$ has been measured in proton$-$proton collisions at $\sqrt{s}=13$ TeV, using $36.1$ fb$^{-1}$ of data collected in 2015$-$16 by the ATLAS experiment at the LHC. Using events with an opposite-charge $e\mu$ pair and $b$-tagged jets, the cross-section is measured to be: \begin{equation}\nonumber \sigma_{t\bar{t}} = 826.4 \pm 3.6\,\mathrm{(stat)}\ \pm 11.5\,\mathrm{(syst)}\ \pm 15.7\,\mathrm{(lumi)}\ \pm 1.9\,\mathrm{(beam)}\,\mathrm{pb}, \end{equation} where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the LHC beam energy, giving a total uncertainty of 2.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. It is used to determine the top quark pole mass via the dependence of the predicted cross-section on $m_t^{\mathrm{pole}}$, giving $m_t^{\mathrm{pole}}=173.1^{+2.0}_{-2.1}$ GeV. It is also combined with measurements at $\sqrt{s}=7$ TeV and $\sqrt{s}=8$ TeV to derive ratios and double ratios of $t\bar{t}$ and $Z$ cross-sections at different energies. The same event sample is used to measure absolute and normalised differential cross-sections as functions of single-lepton and dilepton kinematic variables, and the results compared with predictions from various Monte Carlo event generators.

Item Type:	Article
Additional Information:	88 pages in total, author list starting on page 72, 22 figures, 24 tables, published version in Eur. Phys. J. C. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2018-17/
Uncontrolled Keywords:	hep-ex, hep-ex
Depositing User:	Symplectic Admin
Date Deposited:	06 Jul 2020 11:02
Last Modified:	18 Jan 2023 23:47
DOI:	10.1140/epjc/s10052-020-7907-9
Open Access URL:	https://doi.org/10.1140/epjc/s10052-020-7907-9
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3092127