Measurements of differential t-channel single top-quark production cross-sections in proton–proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS detector

Abstract

Proton-proton collision data at a centre-of-mass energy of 8 TeV recorded with the ATLAS detector in 2012, corresponding to an integrated luminosity of 20.2 fb^-1, are used to measure absolute and normalised differential cross-sections of single top quarks produced in the <i>t</i>-channel. They are measured as a function of the transverse momentum and the absolute value of the rapidity of the top quarks and the top antiquarks at both parton level and particle level. The transverse momentum and rapidity differential cross-sections of the scattered light-quark jets are extracted at particle level. Selected events contain one charged lepton, missing transverse momentum, and two jets, one of which is identified as originating from a <i>b</i>-quark. An artificial neural network is used to separate the<i>t</i>-channel signal from its background. A cut on the neural network discriminator is applied to achieve a good signal-to-background ratio. The differential cross-sections are extracted using an iterative Bayesian unfolding. The measured cross-sections are compared to different Monte Carlo predictions as well as to available fixed-order QCD calculations. All results agree with the Standard Model predictions.