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

Abstract

Various differential cross-sections are measured in top-quark pair (tt¯) events produced in proton-proton collisions at a centre-of-mass energy of sqrt(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 of a top-quark proxy referred to as the pseudo-top-quark whose dependence on theoretical models is minimal. The pseudo-top-quark can be defined in terms of either reconstructed detector objects or stable particles in an analogous way. The measurements are performed on tt¯ 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. The cross-section is measured as a function of the transverse momentum and rapidity of both the hadronic and leptonic pseudo-top-quark as well as the transverse momentum, rapidity and invariant mass of the pseudo-top-quark pair system. The measurements are corrected for detector effects and are presented within a kinematic range that closely matches the detector acceptance. 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.


Tutti gli autori

  • G. AAD , G. CHIODINI , E. GORINI , M. PRIMAVERA , S. SPAGNOLO , A. VENTURA , ET AL.

Titolo volume/Rivista

JOURNAL OF HIGH ENERGY PHYSICS


Anno di pubblicazione

2015

ISSN

1126-6708

ISBN

Non Disponibile


Numero di citazioni Wos

13

Ultimo Aggiornamento Citazioni

28/04/2018


Numero di citazioni Scopus

20

Ultimo Aggiornamento Citazioni

28/04/2018


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile