Comprehensive measurements of t-channel single top-quark production cross sections at √s = 7 TeV with the ATLAS detector

This article presents measurements of the t-channel single top-quark (t) and top-antiquark (¯t) total cross sections σðtqÞ and σð¯tqÞ, their ratio Rt ¼ σðtqÞ=σð¯tqÞ, and a measurement of the inclusive cross section σðtq þ ¯tqÞ in proton-proton collisions at ¼ 7 TeV at the LHC. Differential sections for the tq and ¯tq processes are measured as a function of the transverse momentum and the value of the rapidity of t and ¯t, respectively. The analyzed data set was recorded with the ATLAS and corresponds to an integrated luminosity of 4.59 fb−1. Selected events contain one charged , large missing transverse momentum, and two or three jets. The cross sections are measured performing a binned maximum-likelihood fit to the output distributions of neural networks. The measurements are σðtqÞ ¼ 46 1ðstatÞ 6ðsystÞ pb, σð¯tqÞ ¼ 23 1ðstatÞ 3ðsystÞ pb, ¼ 2.04 0.13ðstatÞ 0.12ðsystÞ, and σðtq þ ¯tqÞ ¼ 68 2ðstatÞ 8ðsystÞ pb, consistent with the Model expectation. The uncertainty on the measured cross sections is dominated by systematic , while the uncertainty on Rt is mainly statistical. Using the ratio of σðtq þ ¯tqÞ to its theoretical , and assuming that the top-quark-related CKM matrix elements obey the relation ≫ jVtsj; jVtdj, we determine jVtbj ¼ 1.02 0.07.