# Measurement of the toverline{t}W and toverline{t}Z production cross sections in pp collisions at sqrt{s}=8 TeV with the ATLAS detector

Journal of High Energy Physics

, 2015:172

First Online: 24 November 2015Received: 18 September 2015Accepted: 03 November 2015 Abstract

The production cross sections of top-quark pairs in association with massive vector bosons have been measured using data from pp collisions at \ \sqrt{s}=8 \ TeV. The dataset corresponds to an integrated luminosity of 20.3 fb 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 \ t\overline{t}W \ and \ t\overline{t}Z \ processes simultaneously yields a significance of 5.0σ 4.2σ over the background-only hypothesis for \ t\overline{t}W \ \ t\overline{t}Z \ production. The measured cross sections are \ {\sigma} {t\overline{t}W}={369} {-91}^{+100} \ fb and \ {\sigma} {t\overline{t}Z}={176} {-52}^{+58} \ fb. The background-only hypothesis with neither \ t\overline{t}W \ nor \ t\overline{t}Z \ production is excluded at 7.1σ. All measurements are consistent with next-to-leading-order calculations for the \ t\overline{t}W \ and \ t\overline{t}Z \ processes.Open image in new windowKeywordsElectroweak interaction Hadron-Hadron scattering Top physics ArXiv ePrint: 1509.05276

Deceased W. Blum, H. M. Braun, V. Chernyatin, B. A. Dolgoshein, A. A. Komar, K.W. McFarlane, S. V. Mouraviev, F. Pastore, G. Sauvage, D. M. Seliverstov, A. N. Sisakyan, R. D. St. Denis, R. P. Thun, T. Todorov

Author: The ATLAS collaboration - G. Aad - B. Abbott - J. Abdallah - O. Abdinov - R. Aben - M. Abolins - O. S. AbouZeid - H. Abra