Measurements of top-quark pair to $Z$-boson cross-section ratios at $\sqrt{s}=13,8,7$TeV with the ATLAS detector

Abstract

Ratios of top-quark pair to $Z$-boson cross sections measured from proton--proton collisions at the LHC centre-of-mass energies of $\sqrt{s}=13$TeV, 8TeV, and 7TeV are presented by the ATLAS Collaboration. Single ratios, at a given $\sqrt{s}$ for the two processes and at different $\sqrt{s}$ for each process, as well as double ratios of the two processes at different $\sqrt{s}$, are evaluated. The ratios are constructed using previously published ATLAS measurements of the $t\overline{t}$ and $Z$-boson production cross sections, corrected to a common phase space where required, and a new analysis of $Z\to {\ell }^{+}{\ell }^{-}$ where $\ell =e,\mu$ at $\sqrt{s}=13$TeV performed with data collected in 2015 with an integrated luminosity of $3.2$fb${}^{-1}$. Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the $Z\to e^{+}{e}^{-}$ and the $Z\to {\mu }^{+}{\mu }^{-}$ channels for each $\sqrt{s}$ value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-$x$ values near 0.1 and the light-quark sea for $x<0.02$.

arXiv comment55 pages in total, author list starting page 34, 9 figures, 18 tables, submitted to J. High Energy Phys. All figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2016-02/

References in corpus (63)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• A Brief Introduction to PYTHIA 8.1
• Parton distributions for the LHC
• New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
• A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
• A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Parton distributions for the LHC Run II
• New parton distributions for collider physics
• Event generation with SHERPA 1.1
• HERWIG 6.5: an event generator for Hadron Emission Reactions With Interfering Gluons (including supersymmetric processes)
• The ATLAS Simulation Infrastructure
• PDF4LHC recommendations for LHC Run II
• New parton distribution functions from a global analysis of quantum chromodynamics
• Parton distributions in the LHC era: MMHT 2014 PDFs
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• Top++: a program for the calculation of the top-pair cross-section at hadron colliders
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• PHOTOS Monte Carlo: a precision tool for QED corrections in Z and W decays
• Tuning Monte Carlo Generators: The Perugia Tunes
• An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC
• High-precision QCD at hadron colliders: electroweak gauge boson rapidity distributions at NNLO
• Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Percent level precision physics at the Tevatron: first genuine NNLO QCD corrections to q qbar -> t tbar + X
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order
• Muon reconstruction performance of the ATLAS detector in proton--proton collision data at $\sqrt{s}$=13 TeV
• NNLO corrections to top-pair production at hadron colliders: the all-fermionic scattering channels
• NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction
• Improved luminosity determination in pp collisions at sqrt(s) = 7 TeV using the ATLAS detector at the LHC
• NLO vector-boson production matched with shower in POWHEG
• Hadronic top-quark pair production with NNLL threshold resummation
• Luminosity determination in pp collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector at the LHC
• Combining QCD and electroweak corrections to dilepton production in FEWZ
• Measurement of the $Z/{\gamma }^{\ast }$ boson transverse momentum distribution in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detector
• Measurement of the Inclusive W and Z Production Cross Sections in pp Collisions at sqrt(s) = 7 TeV
• Electron efficiency measurements with the ATLAS detector using 2012 LHC proton-proton collision data
• Measurement of the inclusive W+- and Z/gamma cross sections in the electron and muon decay channels in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
• The ABM parton distributions tuned to LHC data
• Measurement of the transverse momentum and ${\varphi }_{\eta }^{\ast }$ distributions of Drell-Yan lepton pairs in proton-proton collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Radiative corrections to the neutral-current Drell-Yan process in the Standard Model and its minimal supersymmetric extension
• Measurement of $W^{\pm }$ and $Z$-boson production cross sections in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Determination of the strange quark density of the proton from ATLAS measurements of the W->l nu and Z->ll cross sections
• The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II
• Measurement of the $t\bar{t}$ production cross-section using $e\mu$ events with $b$-tagged jets in $pp$ collisions at $\sqrt{s}=7$ and 8 TeV with the ATLAS detector
• PDF reweighting in the Hessian matrix approach
• Measurement of the Inclusive ep Scattering Cross Section at Low Q^2 and x at HERA
• Measurement of the differential and double-differential Drell-Yan cross sections in proton-proton collisions at sqrt(s) = 7 TeV
• Measurement of inclusive W and Z boson production cross sections in pp collisions at sqrt(s) = 8 TeV
• Measurement of the top quark pair production cross-section with ATLAS in the single lepton channel
• Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at $\sqrt{s}=8$ TeV with ATLAS
• Measurements of differential and double-differential Drell-Yan cross sections in proton-proton collisions at 8 TeV
• Measurement of the t-tbar production cross section in the e-mu channel in proton-proton collisions at sqrt(s) = 7 and 8 TeV
• Cross Section Ratios between different CM energies at the LHC: opportunities for precision measurements and BSM sensitivity
• Measurement of the t t-bar production cross section in pp collisions at sqrt(s) = 7 TeV with lepton + jets final states
• Measurement of the top quark pair production cross section in proton-proton collisions at sqrt(s) = 13 TeV
• In-medium covariant propagator of baryons under a strong magnetic field: effect of the intrinsic magnetic moments
• Measurements of fiducial cross-sections for $t\bar{t}$ production with one or two additional $b$-jets in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector
• Measurements of the t-tbar production cross section in lepton+jets final states in pp collisions at 8 TeV and ratio of 8 to 7 TeV cross sections
• SANC integrator in the progress: QCD and EW contributions
• QED Bremsstrahlung in decays of electroweak bosons

Cited by in corpus (20)

• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Measurement of the Drell--Yan triple-differential cross section in $pp$ collisions at $\sqrt{s}=8$ TeV
• DYTurbo: Fast predictions for Drell-Yan processes
• A new simple PDF parametrization: improved description of the HERA data
• Measurements of $W$ and $Z$ boson production in $pp$ collisions at $\sqrt{s}=5.02$ TeV with the ATLAS detector
• Observation of a pseudoscalar excess at the top quark pair production threshold
• Parton distributions need representative sampling
• On Light Resonance Interpretations of the B Decay Anomalies
• Heavy-flavor parton distributions without heavy-flavor matching prescriptions
• Measurement of $W^{\pm }$-boson and $Z$-boson production cross-sections in $pp$ collisions at $\sqrt{s}=2.76$ TeV with the ATLAS detector
• Search for heavy pseudoscalar and scalar bosons decaying to a top quark pair in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Precise measurements of $W$- and $Z$-boson transverse momentum spectra with the ATLAS detector using $pp$ collisions at $\sqrt{s}=5.02$ TeV and $13$ TeV
• Defiducialization: Providing Experimental Measurements for Accurate Fixed-Order Predictions
• Data-Driven Precision Luminosity Measurements with Z Bosons at the LHC and HL-LHC
• On the Model Dependence of Fiducial Cross Section Measurements in View of Reinterpretations
• Parton distribution functions and QCD coupling constant from LHC and non-LHC data
• Search for Dark Photons in Rare $Z$ Boson Decays with the ATLAS Detector
• Inclusive $t\bar{t}$ cross-section measurements at LHC
• Measurement of the $t\bar{t}$ production cross-section and lepton differential distributions in $e\mu$ dilepton events from $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• TOP2017: Experimental Summary