Single top-quark production measurements with ATLAS at the LHC

Laboratoire de Physique Subatomique et de Cosmologie, Université Joseph Fourier and CNRS/IN2P3 and Institut National Polytechnique de Grenoble, Grenoble, France

^a lleres@lpsc.in2p3.fr

Abstract

We present cross-section measurements of single top-quark production in the t-channel and associated Wt production modes using pp collision data recorded with the ATLAS detector at the LHC. The t-channel total cross-section is measured at √s = 7 TeV and at √s = 8 TeV with an integrated luminosity of 1.04 fb⁻¹ and 5.8 fb⁻¹, respectively. The t-channel top-quark and top-antiquark production cross sections and their ratio are also measured at 7 TeV with 4.7 fb⁻¹ of data. Evidence for the Wt associated production is found at 7 TeV in the dileptonic channel using a luminosity of 2.05 fb⁻¹. The measured cross-sections as well as the top-antitop ratio are in good agreement with the Standard Model predictions. The coupling strength |V_tb| is determined from the ratio of the measured to the theoretically predicted cross sections assuming that |V_ts| and |V_td| are small. The extracted values are all compatible with the Standard Model and with previous measurements.