Measurement of the inclusive and fiducial tt ¯ production cross-sections in the lepton+jets channel in pp collisions at s √ =8 TeV with the ATLAS detector

Abraham, N L, Allbrooke, B M M, Asquith, L, Cerri, A, Chavez Barajas, C A, De Santo, A, Jones, S, Lerner, G, Miano, F, Salvatore, F, Santoyo Castillo, I, Shaw, K, Shehu, C Y, Stevenson, T J, Suruliz, K, Sutton, M R, Tresoldi, F, Vivarelli, I, Winkels, E, Winston, O J, The ATLAS Collaboration, and others, (2018) Measurement of the inclusive and fiducial tt ¯ production cross-sections in the lepton+jets channel in pp collisions at s √ =8 TeV with the ATLAS detector. European Physical Journal C: Particles and Fields, 78 (487). pp. 1-31. ISSN 1434-6044

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Abstract

The inclusive and fiducial tt ¯ production cross-sections are measured in the lepton+jets channel using 20.2 fb −1 of proton-proton collision data at a centre-of-mass energy of 8 TeV recorded with the ATLAS detector at the LHC. Major systematic uncertainties due to the modelling of the jet energy scale and b -tagging efficiency are constrained by separating selected events into three disjoint regions. In order to reduce systematic uncertainties in the most important background, the W+jets process is modelled using Z+jets events in a data-driven approach. The inclusive tt ¯ cross-section is measured with a precision of 5.7% to be σ inc (tt ¯ ) = 248.3 ± 0.7 (stat.) ± 13.4 (syst.) ± 4.7 (lumi.) pb, assuming a top-quark mass of 172.5 GeV. The result is in agreement with the Standard Model prediction. The cross-section is also measured in a phase space close to that of the selected data. The fiducial cross-section is σ fid (tt ¯ ) = 48.8 ± 0.1 (stat.) ± 2.0 (syst.) ± 0.9 (lumi.) pb with a precision of 4.5%.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups: Experimental Particle Physics Research Group
Subjects: Q Science > QC Physics
Depositing User: Alice Jackson
Date Deposited: 09 Nov 2018 16:39
Last Modified: 02 Jul 2019 13:51
URI: http://sro.sussex.ac.uk/id/eprint/80107

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