Measurement of the charge asymmetry in dileptonic decays of top quark pairs in $pp$ collisions at $\sqrt{s}=7$ TeV using the ATLAS detector

Abstract

A measurement of the top-antitop ($t\bar{t}$) charge asymmetry is presented using data corresponding to an integrated luminosity of 4.6 fb${}^{-1}$ of LHC $pp$ collisions at a centre-of-mass energy of 7 TeV collected by the ATLAS detector. Events with two charged leptons, at least two jets and large missing transverse momentum are selected. Two observables are studied: $A_{\text{C}}^{\ell \ell }$ based on the identified charged leptons, and $A_{\text{C}}^{t\bar{t}}$, based on the reconstructed $t\bar{t}$ final state. The asymmetries are measured to be \begin{eqnarray*} A^{\ell\ell}_{\textrm{C}} & = & 0.024 \pm 0.015 ~\textrm{(stat.)} \pm 0.009 ~\textrm{(syst.)}, \end{eqnarray*} \begin{eqnarray*} A^{t\bar{t}}_{\textrm{C}} & = & 0.021 \pm 0.025 ~\textrm{(stat.)} \pm 0.017 ~\textrm{(syst.)}. \end{eqnarray*} The measured values are in agreement with the Standard Model predictions.

33 pages plus author list + cover pages (57 pages total), 8 figures, 11 tables, published version, all figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2013-09/

References in corpus (26)

• PYTHIA 6.4 Physics and Manual
• Parton distributions for the LHC
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• New parton distributions for collider physics
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Single-top hadroproduction in association with a W boson
• The PDF4LHC Working Group Interim Recommendations
• Jet energy measurement and its systematic uncertainty in proton-proton collisions at $\sqrt{s}=7$ TeV with the ATLAS detector
• Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton-proton collision data
• Parton Distributions for LHC
• Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton-proton collision data
• Effective-Field-Theory Approach to Top-Quark Production and Decay
• Top pair invariant mass distribution: a window on new physics
• Effective four-fermion operators in top physics: a roadmap
• Probing the Tevatron t tbar asymmetry at LHC
• Top Quark Pairs at High Invariant Mass - A Model-Independent Discriminator of New Physics at the LHC
• Inclusive and differential measurements of the t t-bar charge asymmetry in proton-proton collisions at sqrt(s) = 7 TeV
• Massive color-octet bosons and the charge asymmetries of top quarks at hadron colliders
• Measurement of the forward-backward asymmetry in top quark-antiquark production in ppbar collisions using the lepton+jets channel
• Asymmetries in top quark pair production at hadron colliders
• Measurement of the inclusive leptonic asymmetry in top-quark pairs that decay to two charged leptons at CDF
• Data driving the top quark forward--backward asymmetry with a lepton-based handle
• Measurement of the forward-backward asymmetry in the distribution of leptons in $t\bar{t}$ events in the lepton+jets channel
• Application of the Principle of Maximum Conformality to the Top-Quark Charge Asymmetry at the LHC
• Portrait of a colour octet

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