Measurement of the $t\bar{t}W$ and $t\bar{t}Z$ production cross sections in $pp$ collisions at $\sqrt{s}=8\mathrm{Te}\mathrm{V}$ with the ATLAS detector

Abstract

The production cross sections of top-quark pairs in association with massive vector bosons have been measured using data from $pp$ collisions at $\sqrt{s}=8\mathrm{Te}\mathrm{V}$. The dataset corresponds to an integrated luminosity of $20.3{\mathrm{fb}}^{-1}$ collected by the ATLAS detector in 2012 at the LHC. Final states with two, three or four leptons are considered. A fit to the data considering the $t\bar{t}W$ and $t\bar{t}Z$ processes simultaneously yields a significance of $5.0\sigma$ ($4.2\sigma$) over the background-only hypothesis for $t\bar{t}W$ ($t\bar{t}Z$) production. The measured cross sections are ${\sigma }_{t\bar{t}W}=369_{-91}^{+100}$ fb and ${\sigma }_{t\bar{t}Z}=176_{-52}^{+58}$ fb. The background-only hypothesis with neither $t\bar{t}W$ nor $t\bar{t}Z$ production is excluded at $7.1\sigma$. All measurements are consistent with next-to-leading-order calculations for the $t\bar{t}W$ and $t\bar{t}Z$ processes.

31 pages plus author list + cover pages (47 pages total), 11 figures,8 tables, submitted to JHEP, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2013-05/

References in corpus (19)

• PYTHIA 6.4 Physics and Manual
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Parton distributions for the LHC
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• New parton distributions for collider physics
• Event generation with SHERPA 1.1
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• Electroweak gauge boson production at hadron colliders through O(alpha_s^2)
• Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production
• NNLL resummation for s-channel single top quark production
• 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
• Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton-proton collision data
• Electron efficiency measurements with the ATLAS detector using 2012 LHC proton-proton collision data
• t tbar W and t tbar Z Hadroproduction at NLO accuracy in QCD with Parton Shower and Hadronization effects
• Efficient Identification of Boosted Semileptonic Top Quarks at the LHC
• Measurements of normalized differential cross-sections for ttbar production in pp collisions at sqrt(s) = 7 TeV using the ATLAS detector
• Measurement of top quark-antiquark pair production in association with a W or Z boson in pp collisions at sqrt(s) = 8 TeV

Cited by in corpus (37)

• The Standard Model as an Effective Field Theory
• Constraining top quark effective theory in the LHC Run II era
• Top-quark pair hadroproduction in association with a heavy boson at NLO+NNLL including EW corrections
• Measurement of the $t\bar{t}Z$ and $t\bar{t}W$ cross sections in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Strong tW Scattering at the LHC
• Measurement of the cross section for top quark pair production in association with a W or Z boson in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Associated production of a top quark pair with a heavy electroweak gauge boson at NLO+NNLL accuracy
• Associated top quark pair production with a heavy boson: differential cross sections at NLO+NNLL accuracy
• Pinning down electroweak dipole operators of the top quark
• Global and optimal probes for the top-quark effective field theory at future lepton colliders
• Measurement of the production cross-section of a single top quark in association with a $Z$ boson in proton--proton collisions at 13 TeV with the ATLAS detector
• Precise predictions for the associated production of a $W$ boson with a top-antitop quark pair at the LHC
• Measurement of the $t\bar{t}Z$ and $t\bar{t}W$ production cross sections in multilepton final states using 3.2 fb${}^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Measurement of the charge asymmetry in top-quark pair production in the lepton-plus-jets final state in $pp$ collision data at $\sqrt{s}=8$ TeV with the ATLAS detector
• Anatomy of inclusive $t\overline{t}W$ production at hadron colliders
• Top-Quark Physics: Status and Prospects
• Modeling uncertainties of $t\bar{t}{W}^{\pm }$ multilepton signatures
• Combined NLO EW and QCD corrections to off-shell $\text{t}\overline{\text{t}}\text{W}$ production at the LHC
• Search for direct pair production of supersymmetric top quarks decaying to all-hadronic final states in pp collisions at sqrt(s) = 8 TeV
• Combined SMEFT interpretation of Higgs, diboson, and top quark data from the LHC
• Top physics at high-energy lepton colliders
• Top-quark physics at the Large Hadron Collider
• New physics and signal-background interference in associated $pp\to HZ$ production
• Production of electroweak bosons at hadron colliders: theoretical aspects
• Electroweak Top Couplings, Partial Compositeness and Top Partner Searches
• Investigating the Quantum Properties of Jets and the Search for a Supersymmetric Top Quark Partner with the ATLAS Detector
• From the 750 GeV Diphoton Resonance to Multilepton Excesses
• Diboson resonances within a custodially protected warped extra-dimensional scenario
• Top quark physics in the Large Hadron Collider era
• Heavy Higgs decay to $t\bar{t}Z$ and constraints on a $750$ GeV pseudoscalar
• Anatomy of the $tthh$ Physics at HL-LHC
• Prompt $J/\psi$ production in associated with top quark pair at the LHC
• Displaced lepton flavour violating signatures of right-handed sneutrinos in $U(1{)}^{\prime }$ supersymmetric models
• Recent Developments in Higher-Order Calculations: Hard Functions at NLO with GoSam
• Measurement of the $t\bar{t}Z$ Production Cross Section in the Final State with Three Charged Leptons using 36.1 fb${}^{-1}$ of $pp$ Collisions at 13 TeV at the ATLAS Detector
• Searches for new interactions within the SMEFT framework at present and future colliders
• Top-quark production measurements