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

Summary, in English

The inclusive and fiducial tt¯ production cross-sections are measured in the lepton+jets channel using 20.2fb-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 σinc(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 σfid(tt¯)=48.8±0.1(stat.)±2.0(syst.)±0.9(lumi.)pb with a precision of 4.5%. © 2018, CERN for the benefit of the ATLAS collaboration.

• Author: M Aaboud; G Aad; B. Abbott; O Abdinov; B Abeloos; S. H. Abidi; Torsten Åkesson; Simona Bocchetta; Caterina Doglioni; Vincent Hedberg; Göran Jarlskog; Charles Kalderon; Edgar Kellermann; Balazs Konya; Else Lytken; Katja Mankinen; Ulf Mjörnmark; Ruth Pöttgen; Trine Poulsen; Oxana Smirnova; Oleksandr Viazlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2018-06
• Language: English
• Publication/Series: European Physical Journal C
• Volume: 78
• Issue: 6
• Links: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048534318&doi=10.1140%2fepjc%2fs10052-018-5904-z&partnerID=40&md5=f736d2ab3e837abf415fe505fd2461c7; http://dx.doi.org/10.1140/epjc/s10052-018-5904-z
• Document type: Journal article
• Publisher: Springer Nature
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044