Measurement of the t ¯ t W and t ¯ t Z production cross sections in pp collisions at √s =8 TeV with the ATLAS detector

Barton, Adam 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 Skinner, Malcolm and Smizanska, Maria and Walder, James William and Wharton, Andy (2015) Measurement of the t ¯ t W and t ¯ t Z production cross sections in pp collisions at √s =8 TeV with the ATLAS detector. Journal of High Energy Physics (11). ISSN 1029-8479

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Abstract

The production cross sections of top-quark pairs in association with massive vector bosons have been measured using data from pp collisions at s√=8 TeV. The dataset corresponds to an integrated luminosity of 20.3 fb−1 collected by the ATLAS detector in 2012 at the LHC. Final states with two, three or four leptons are considered. A fit to the data considering the tt¯W and tt¯Z processes simultaneously yields a significance of 5.0σ (4.2σ) over the background-only hypothesis for tt¯W (tt¯Z) production. The measured cross sections are σtt¯W=369+100−91 fb and σtt¯Z=176+58−52 fb. The background-only hypothesis with neither tt¯W nor tt¯Z production is excluded at 7.1σ. All measurements are consistent with next-to-leading-order calculations for the tt¯W and tt¯Z processes.

Item Type:
Journal Article
Journal or Publication Title:
Journal of High Energy Physics
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3106
Subjects:
ID Code:
78045
Deposited By:
Deposited On:
28 Jan 2016 15:32
Refereed?:
Yes
Published?:
Published
Last Modified:
31 Mar 2020 03:51