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
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Authors
Colleges, School and Institutes
External organisations
- University Politehnica Bucharest
- Faculdade de Ciencias e Tecnologia, New University of Lisbon
- Centre National de l’Energie des Sciences Techniques Nucleaires
- European Organization for Nuclear Research (CERN)
- Université Mohamed Premier and LPTPM
- CNRS/IN2P3
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA; Department of Chemistry and Biochemistry, The University of Oklahoma, Norman, OK, 73019, USA.
- Institute of Physics Azerbaijan National Academy of Sciences
- IN2P3
- University of Toronto
- Santa Cruz Institute for Particle Physics
- SUSSEX UNIVERSITY
- Tel Aviv University
- Technion - Israel Institute of Technology
- University of Oregon
- Stockholm University
- The Oskar Klein Centre
- Department of Physics and Astronomy and INFN
- Abdus Salam International Centre for Theoretical Physics
- Tokyo Metropolitan University
- Electronics and Telecommunications
- Northern Illinois University
- University of Munich
- RUTHERFORD APPLETON LABORATORY
- University of Belgrade
- Alexandru Ioan Cuza University of Iasi
Abstract
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%.
Details
Original language | English |
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Article number | 487 |
Journal | European Physical Journal C |
Volume | 78 |
Issue number | 6 |
Early online date | 12 Jun 2018 |
Publication status | E-pub ahead of print - 12 Jun 2018 |