Various differential cross-sections are measured in top-quark pair (t¯t) events produced in proton-proton collisions at a centre-of-mass energy of √s = 7TeV at the LHC with the ATLAS detector. These differential cross-sections are presented in a data set corresponding to an integrated luminosity of 4.6 fb−1. The differential cross-sections are presented in terms of kinematic variables, such as momentum, rapidity and invariant mass, of a top-quark proxy referred to as the pseudo-top-quark as well as the pseudo-top-quark pair system. The dependence of the measurement on theoretical models is minimal. The measurements are performed on t¯t events in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of them tagged as originating from a b-quark. The hadronic and leptonic pseudo-top-quarks are defined via the leptonic or hadronic decay mode of the W boson produced by the top-quark decay in events with a single charged lepton. Differential cross-section measurements of the pseudo-top-quark variables are compared with several Monte Carlo models that implement next-to-leading order or leading-order multi-leg matrix-element calculations

Aad, G., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdinov, O., Aben, R., et al. (2015). Differential top-antitop cross-section measurements as a function of observables constructed from final-state particles using pp collisions at s = 7 $$ \sqrts=7 $$ TeV in the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS, 2015(6), 100-1-100-56 [10.1007/JHEP06(2015)100].

Differential top-antitop cross-section measurements as a function of observables constructed from final-state particles using pp collisions at s = 7 $$ \sqrts=7 $$ TeV in the ATLAS detector

ALBERGHI, GIAN LUIGI;BELLAGAMBA, LORENZO;BOSCHERINI, DAVIDE;BRUNI, ALESSIA;BRUNI, GRAZIANO;DE CASTRO, STEFANO;FABBRI, LAURA;FRANCHINI, MATTEO;GABRIELLI, ALESSANDRO;GIACOBBE, BENEDETTO;LASAGNI MANGHI, FEDERICO;MASSA, LORENZO;MENGARELLI, ALBERTO;