Measurement of T-Channel Single-Top Production in Pp Collisions at √s=5.02 Tev With the Atlas Detector

Abstract

The observation of the electroweak production of single-top-quarks is made using 255 pb(-1) of proton-proton collision data recorded at root s = 5.02 TeV with the ATLAS detector at the Large Hadron Collider. An event selection is used to identify single-top-quark candidates arising from..-channel production with the top quark decaying semi-leptonically. Events passing the selection are then used to measure the inclusive cross-section for the combined production of single-top-quarks and antiquarks, sigma(tq + (t) over barq), and the ratio R-t between these two. They are measured to be sigma(tq + (t) over barq) = 27.1(-4.1)(+4.4)(stat.)(-3.7)(+4.4)(syst.) pb and R-t = 2.73(-0.82)(+1.43)(stat.)(-0.29)(+1.01)(syst.). The individual single-top-quark (tq) and single-top-antiquark ((t) over barq) production cross-sections are measured to be sigma(tq) = 19.8(-3.1)(+3.9)(stat.)(-2.2)(+2.9)(syst.) pb and sigma((t) over barq) = 7.3(-2.1)(+3.2)(stat.)(-1.5)(+2.8)(syst.) pb. All measurements are in good agreement with the Standard Model predictions.