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Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \(\sqrt{s}=7\) TeV

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Abstract

A measurement of the production cross-section for top quark pairs (\(t\bar{t}\)) in pp collisions at \(\sqrt{s}=7\ \ \mbox{TeV}\) is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron e or muon μ) with large missing transverse energy and at least four jets, and dilepton (ee, μμ or ) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb−1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\(t\bar{t}\) Standard Model processes are estimated using data-driven methods and determined to be 12.2±3.9 events and 2.5±0.6 events, respectively. The kinematic properties of the selected events are consistent with SM \(t\bar{t}\) production. The inclusive top quark pair production cross-section is measured to be

$$\sigma_{t\bar{t}}=145\pm31(\mathrm{stat.}) {}^{+42}_{-27}(\mathrm {syst.})\ \mbox{pb}.$$

The measurement agrees with perturbative QCD calculations.

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The ATLAS Collaboration., Aad, G., Abbott, B. et al. Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \(\sqrt{s}=7\) TeV. Eur. Phys. J. C 71, 1577 (2011). https://doi.org/10.1140/epjc/s10052-011-1577-6

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  • DOI: https://doi.org/10.1140/epjc/s10052-011-1577-6

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