Measurement of the ttW and ttZ production cross sections in pp collisions at √s=8 TeV with the ATLAS detector

Aad, G. and Abbott, B. and Abdallah, J. and Abdinov, O. and Aben, R. and Krasznahorkay, Attila and Nagai, Yoshikazu and Pásztor, Gabriella and Tóth, József (2015) Measurement of the ttW and ttZ production cross sections in pp collisions at √s=8 TeV with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS (11). ISSN 1126-6708

Preview

Text 1509.05276.pdf Available under License Creative Commons Attribution. Download (1MB) | Preview

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 corres- ponds 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 t¯tW and t¯tZ processes simultaneously yields a significance of 5.0σ (4.2σ) over the background-only hypothesis for t¯tW (t¯tZ) production. The measured cross sections are σt¯tW = 369+100 −91 fb and σt¯tZ = 176+58 −52 fb. The background-only hypothesis with neither t¯tW nor t¯tZ production is excluded at 7.1σ. All measurements are consistent with next-to- leading-order calculations for the t¯tW and t¯tZ processes.

Actions (login required)

Edit Item