Measurements of fiducial cross-sections for tt¯ production with one or two additional b-jets in pp collisions at √s=8 TeV using the ATLAS detector

Barton, Adam Edward and Beattie, Michael and Borissov, Guennadi and Bouhova-Thacker, Evelina Vassileva and Dearnaley, William and Fox, Harald and Grimm, Kathryn Ann Tschann and Henderson, Robert Charles William and Hughes, Gareth and Jones, Roger William Lewis and Kartvelishvili, Vakhtang and Long, Robin Eamonn and Love, Peter Allan and Maddocks, Harvey and Smizanska, Maria and Walder, James William and Wharton, Andy (2016) Measurements of fiducial cross-sections for tt¯ production with one or two additional b-jets in pp collisions at √s=8 TeV using the ATLAS detector. European Physical Journal C: Particles and Fields, 76 (1). ISSN 1434-6044

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Abstract

Fiducial cross-sections for tt¯ production with one or two additional b-jets are reported, using an integrated luminosity of 20.3 fb−1 of proton–proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-section times branching ratio for tt¯ events with at least one additional b-jet is measured to be 950 ± 70 (stat.) +240−190 (syst.) fb in the lepton-plus-jets channel and 50 ± 10 (stat.) +15−10 (syst.) fb in the eμeμ channel. The cross-section times branching ratio for events with at least two additional b-jets is measured to be 19.3 ± 3.5 (stat.) ± 5.7 (syst.) fb in the dilepton channel (eμeμ, μμμμ, and ee) using a method based on tight selection criteria, and 13.5 ± 3.3 (stat.) ± 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 ± 0.33 (stat.) ± 0.28 (syst.)% for the ratio of tt¯ production with two additional b-jets to tt¯ production with any two additional jets. All measurements are in good agreement with recent theory predictions.

Item Type: Journal Article
Journal or Publication Title: European Physical Journal C: Particles and Fields
Uncontrolled Keywords: /dk/atira/pure/subjectarea/asjc/2200/2201
Subjects:
Departments: Faculty of Science and Technology > Physics
ID Code: 78874
Deposited By: ep_importer_pure
Deposited On: 31 Mar 2016 14:14
Refereed?: Yes
Published?: Published
Last Modified: 13 Nov 2019 06:46
URI: https://eprints.lancs.ac.uk/id/eprint/78874

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