Journal Article

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

Alessandro Gabrielli, Michel Vetterli, G. Khoriauli, L. Mazzaferro, Chikara Fukunaga, Stephan Hageböck, Andreas Wildauer, Ayda Beddall, Leonid Serkin, Alessandra Ciocio, David Milstead, Konstantin Vorobev, G. Eigen, Markus Nordberg, Andrey Minaenko, Evangelos Leonidas Gkougkousis, Hidetoshi Otono, Guillaume Unal, L. Bellagamba, T. Kohriki, W. J. Murray, A. Korn, Bengt Lund-Jensen, Y. B. Pan, J. Bronner, A. Kapliy, Andrew Pilkington, Moritz Kretz, Sebastien Prince, C. Padilla Aranda, V. Sopko, Till Eifert, J. Proudfoot, Michel Lefebvre, D. Chakraborty, Göran Jarlskog, Jörgen Sjölin, R. W. L. Jones, Francesco Nuti, R. Cantrill, D. della Volpe, Reda Tafirout, Anum Qureshi, Nan Lu, E. Pueschel, K. Mahboubi, Daniel Tovey, Alexander Khanov, Akira Yamamoto, Helio Takai, G. Nunes Hanninger, J. Keung, Francisco Anuar Arduh, J. Jimenez Pena, Marino Romano, Fabian-Phillipp Tepel, Gorm Aske Gram Krohn Galster, Reyhaneh Rezvani, Andrey Karyukhin, J. N. Butler, Ljiljana Morvaj, Liza Mijović, Richard Brenner, Nicolas Berger, Ryan Reece, M. Della Pietra, Theodoros Alexopoulos, Michael Begel, Paul Dervan, F. Tarrade, Avi Gershon, Marco Schio

2015

Overview

A bstract 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 = 7 TeV 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.

• Publisher: Springer Berlin Heidelberg
• Subject: 7000 GeV-cms / acceptance / CERN LHC Coll / Classical and Quantum Gravitation / cross section: measured / differential cross section: measured / Elementary Particles / experimental results / final state: ((n)jet lepton) / Hadron-Hadron Scattering / Hadron-Hadron Scattering; Top physics / Hadron-Hadron Scattering; Top physics; High Energy Physics; LHC; ATLAS / Hadron-Hadron Scattering; Top physics; Nuclear and High Energy Physics / higher-order: 0 / higher-order: 1 / info:eu-repo/classification/ddc/530 / kinematics / model: minimal / Nuclear and High Energy Physics / numerical calculations: Monte Carlo / p p: colliding beams / p p: scattering / particle: stability / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Quantum Physics / rapidity dependence / Regular Article - Experimental Physics / Relativity Theory / Settore FIS/01 - FISICA SPERIMENTALE / String Theory / Top physic / Top physics / top: pair production / transverse momentum dependence / W: decay modes