Measurement of the $t\bar{t}$ cross section and its ratio to the $Z$ production cross section using $pp$ collisions at $\sqrt{s}=13.6$ TeV with the ATLAS detector

Abstract

The inclusive top-quark-pair production cross section ${\sigma }_{t\bar{t}}$ and its ratio to the $Z$-boson production cross section have been measured in proton--proton collisions at $\sqrt{s}=13.6$ TeV, using 29 fb${}^{-1}$ of data collected in 2022 with the ATLAS experiment at the Large Hadron Collider. Using events with an opposite-charge electron-muon pair and $b$-tagged jets, and assuming Standard Model decays, the top-quark-pair production cross section is measured to be ${\sigma }_{t\bar{t}}=850\pm 3(stat.)\pm 18(syst.)\pm 20(lumi.)$ pb. The ratio of the $t\bar{t}$ and the $Z$-boson production cross sections is also measured, where the $Z$-boson contribution is determined for inclusive $e^{+}{e}^{-}$ and ${\mu }^{+}{\mu }^{-}$ events in a fiducial phase space. The relative uncertainty on the ratio is reduced compared to the $t\bar{t}$ cross section, thanks to the cancellation of several systematic uncertainties. The result for the ratio, $R_{t\bar{t}/Z}=1.145\pm 0.003(stat.)\pm 0.021(syst.)\pm 0.002(lumi.)$ is consistent with the Standard Model prediction using the PDF4LHC21 PDF set.

arXiv comment41 pages in total, author list starting page 24, 4 figures, 2 tables, submitted to Phys. Lett. B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2023-21/

References in corpus (43)

• FastJet user manual
• Herwig++ Physics and Manual
• Parton distributions with LHC data
• The ATLAS Simulation Infrastructure
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• Scattering Amplitudes with Open Loops
• EPOS LHC : test of collective hadronization with LHC data
• Top++: a program for the calculation of the top-pair cross-section at hadron colliders
• Herwig 7.0 / Herwig++ 3.0 Release Note
• Event Generation with Sherpa 2.2
• An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC
• QCD matrix elements + parton showers: The NLO case
• High-precision QCD at hadron colliders: electroweak gauge boson rapidity distributions at NNLO
• Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO
• QCD matrix elements and truncated showers
• Collier: a fortran-based Complex One-Loop LIbrary in Extended Regularizations
• New CTEQ global analysis of quantum chromodynamics with high-precision data from the LHC
• Percent level precision physics at the Tevatron: first genuine NNLO QCD corrections to q qbar -> t tbar + X
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• Muon reconstruction performance of the ATLAS detector in proton--proton collision data at $\sqrt{s}$=13 TeV
• A critical appraisal of NLO+PS matching methods
• OpenLoops 2
• Performance of pile-up mitigation techniques for jets in $pp$ collisions at $\sqrt{s}=8$ TeV using the ATLAS detector
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• Parton distributions from LHC, HERA, Tevatron and fixed target data: MSHT20 PDFs
• Parton Distribution Functions, ${\alpha }_s$ and Heavy-Quark Masses for LHC Run II
• The Path to Proton Structure at One-Percent Accuracy
• Combining QCD and electroweak corrections to dilepton production in FEWZ
• ATLAS $b$-jet identification performance and efficiency measurement with $t\bar{t}$ events in $pp$ collisions at $\sqrt{s}=13$ TeV
• Jet reconstruction and performance using particle flow with the ATLAS Detector
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• ATLAS data quality operations and performance for 2015-2018 data-taking
• Fully differential NNLO computations with MATRIX
• Electron reconstruction and identification in the ATLAS experiment using the 2015 and 2016 LHC proton-proton collision data at $\sqrt{s}$ = 13 TeV
• The PDF4LHC21 combination of global PDF fits for the LHC Run III
• The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II
• Top-quark pair hadroproduction at next-to-next-to-leading order in QCD
• Measurement of the $t\bar{t}$ production cross-section using $e\mu$ events with $b$-tagged jets in $pp$ collisions at $\sqrt{s}=7$ and 8 TeV with the ATLAS detector
• Measurement of the top quark pair production cross-section with ATLAS in the single lepton channel
• Measurement of the t t-bar production cross section in pp collisions at sqrt(s) = 7 TeV with lepton + jets final states
• First observation of top quark production in the forward region
• Measurements of the t-tbar production cross section in lepton+jets final states in pp collisions at 8 TeV and ratio of 8 to 7 TeV cross sections
• Emulating the impact of additional proton-proton interactions in the ATLAS simulation by pre-sampling sets of inelastic Monte Carlo events

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• NNLO PDFs driven by top-quark data
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