Contact: ATLAS Top Working Group Conveners

For further information and feedback, please contact the group conveners: atlas-phys-top-conveners. (See here for a list of previous top group conveners)

ttbar cross-section plots :

Context | Preview |
---|---|

Summary of LHC and Tevatron measurements of the top-pair production cross-section as a function of the centre-of-mass energy compared
to the NNLO QCD calculation complemented with NNLL resummation (top++2.0). The theory band represents uncertainties due to
renormalisation and factorisation scale, parton density functions and the strong coupling.
The measurements and the theory calculation are quoted at m_{top}=172.5 GeV.
Measurements made at the same centre-of-mass energy are slightly offset for clarity.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of measurements of the top-pair production cross-section at 13 TeV compared to the
exact NNLO QCD calculation complemented with NNLL resummation (top++2.0) using four PDF sets.
The theory bands represent uncertainties due to renormalisation and factorisation scale, parton density functions and the strong coupling.
The measurements and the theory calculation are quoted at m_{top}=172.5 GeV.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of measurements of the top-pair production cross-section at 8 TeV compared to the
exact NNLO QCD calculation complemented with NNLL resummation (top++2.0) using four different PDF sets.
The theory bands represent uncertainties due to renormalisation and factorisation scale, parton density functions and the strong coupling. The measurements and the theory calculation are quoted at m_{top}=172.5 GeV.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of measurements of the top-pair production cross-section at 8 TeV compared to the
exact NNLO QCD calculation complemented with NNLL resummation (top++2.0 ).
The theory band represents uncertainties due to renormalisation and factorisation scale, parton density functions and the strong coupling. The measurements and the theory calculation are quoted at the current world average m_{top}=173.34 GeV.
Status of figure: May 2015 (Top LHC WG 2015)
PDF File Previous Version | |

Summary of measurements of the top-pair production cross-section on ATLAS at 8 TeV compared to the
exact NNLO QCD calculation complemented with NNLL resummation (top++2.0 ).
The theory band represents uncertainties due to renormalisation and factorisation scale, parton density functions and the strong coupling. The measurements and the theory calculation are quoted at m_{top}=172.5 GeV.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Top-pair cross-section measurements at 7 TeV by the ATLAS and CMS collaborations. The band shows the NNLO QCD
calculation complemented with NNLL resummation (top++2.0) using four different PDF sets. The theory bands represent uncertainties due to
renormalisation and factorisation scale, parton density functions and the strong coupling. The measurements and the
theory calculation is quoted at m_{top}=172.5 GeV. The upper part of the figure shows early LHC measurements and
their combination. The lower part summarizes measurements performed after the LHC cross-section combination.
Status of figure: November 2017 (LHCtopWG meeting)
PDF File Previous Version | |

Top-pair cross-section measurements at 7 TeV by the ATLAS collaboration. The band shows the NNLO QCD
calculation complemented with NNLL resummation (top++2.0 ). The theory band represents uncertainties due to
renormalisation and factorisation scale, parton density functions and the strong coupling. The measurements and the
theory calculation is quoted at m_{top}=172.5 GeV.
Status of figure: May 2017
PDF File Previous Version | |

Summary of ATLAS measurements of the top-pair production cross-section as a function of the centre-of-mass energy
compared to the NNLO QCD calculation complemented with NNLL resummation (top++2.0 ). The theory band
represents uncertainties due to renormalisation and factorisation scale, parton density functions and the strong
coupling. The measurements and the theory calculation are quoted at m_{top}=172.5 GeV.
Measurements made at the same centre-of-mass energy are slightly offset for clarity.
Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the transverse momentum of the top quark. The CMS and ATLAS results are compared to NNLO and approximate NNLO calculations. The values for the top-quark mass (mtop), the renormalisation (muR) and factorisation (muF) scales, and the choice of the PDF set used in each calculation are provided. The variable mT is defined as the square root of the sum of the squares of top-quark mass and the transverse momentum of the top quark. Both the CMS and ATLAS measurements are performed assuming a top-quark mass value of 172.5 GeV. The shaded bands show the total uncertainty on the data measurements in each bin. The lower panel shows the ratio of the data measurements and the approximate NNLO calculations to the full NNLO calculation.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the transverse momentum of the top quark.
The CMS and ATLAS results are compared to the NLO and NNLO calculations from arXiv:1606.03350.
The values for the top-quark mass (mtop), the renormalisation (muR) and factorisation (muF) scales,
and the choice of the PDF set used in each calculation are provided.
The variable mT is defined as the square root of the sum of the squares of top-quark mass and the transverse momentum of the top quark.
Both the CMS and ATLAS measurements are performed assuming a top-quark mass value of 172.5 GeV.
The shaded bands show the total uncertainty on the data measurements in each bin.
The lower panel shows the ratio of the data measurements and the NLO calculation to the NNLO calculation.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the invariant mass of the top-quark pair.
The CMS and ATLAS results are compared to the NLO and NNLO calculations from arXiv:1606.03350.
The values for the top-quark mass (mtop), the renormalisation (muR) and factorisation (muF) scales,
and the choice of the PDF set used in each calculation are provided.
Both the CMS and ATLAS measurements are performed assuming a top-quark mass value of 172.5 GeV.
The shaded bands show the total uncertainty on the data measurements in each bin.
The lower panel shows the ratio of the data measurements and NLO calculation to the NNLO calculation.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

ll phase-space normalised differential ttbar cross-section as a function of the transverse momentum of the top quark.
The CMS and ATLAS results are compared to the NNLO calculation.
The values for the top-quark mass (mtop), the renormalisation (muR) and factorisation (muF) scales,
and the choice of the PDF set used in the calculation are provided.
The variable mT is defined as the square root of the sum of the squares of top-quark mass and the transverse momentum of the top quark.
Both the CMS and ATLAS measurements are performed assuming a top-quark mass value of 172.5 GeV.
The shaded bands show the total uncertainty on the data measurements in each bin.
The lower panel shows the ratio of the data measurements to the NNLO calculation.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the transverse momentum of the top quark. The CMS and ATLAS results are compared to predictions from the Powheg+Herwig6 and Powheg+Pythia8 MC generators. The MC samples are generated with the settings described in arXiv:1511.04716. The shaded bands show the total uncertainty on the data measurements in each bin. The lower panel shows the ratio of the data measurements and the Powheg+Pythia8 prediction to the Powheg +Herwig6 prediction.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the invariant mass of the top-quark pair.
The CMS and ATLAS results are compared to NNLO and NLO+NNLL calculations. The values for the top-quark mass (mtop),
the renormalisation (muR) and factorisation (muF) scales, and the choice of the PDF set used in each calculation are provided.
Both the CMS and ATLAS measurements are performed assuming a top-quark mass value of 172.5 GeV.
The shaded bands show the total uncertainty on the data measurements in each bin.
The lower panel shows the ratio of the data measurements and the NLO+NNLL calculation to the NNLO calculation.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the invariant mass of the top-quark pair.
The CMS and ATLAS results are compared to the NNLO calculation.
The values for the top-quark mass (mtop), the renormalisation (muR) and factorisation (muF) scales,
and the choice of the PDF set used in the calculation are provided.
Both the CMS and ATLAS measurements are performed assuming a top-quark mass value of 172.5 GeV.
The shaded bands show the total uncertainty on the data measurements in each bin.
The lower panel shows the ratio of the data measurements to the NNLO calculation.
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the invariant mass of the top-quark pair. The CMS and ATLAS results are compared to predictions from the Powheg+Herwig6 and Powheg+Pythia8 MC generators. The MC samples are generated with the settings described in arXiv: 1511.04716. The shaded bands show the total uncertainty on the data measurements in each bin. The lower panel shows the ratio of the data measurements and the Powheg+Pythia8 prediction to the Powheg +Herwig6 prediction.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

Full phase-space normalised differential ttbar cross-section as a function of the transverse momentum of the top-quark pair. The CMS and ATLAS results are compared to predictions from the Powheg+Herwig6 and Powheg+Pythia8 MC generators. The MC samples are generated with the settings described in arXiv:1511.04716. The shaded bands show the total uncertainty on the data measurements in each bin. The lower panel shows the ratio of the data measurements and the Powheg+Pythia8 prediction to the Powheg +Herwig6 prediction.
Status of figure: November 2016 (LHCtopWG meeting)
PDF File Previous Version | |

single top plots :

Context | Preview |
---|---|

Summary of ATLAS and CMS measurements of the single top production cross-sections in various channels as a function of the center of mass energy. The measurements are compared to theoretical calculations based on: NLO QCD, NLO QCD complemented with NNLL resummation and NNLO QCD (t-channel only).
PDF File Previous Version | |

Summary of ATLAS measurements of the single top production cross-sections in various channels as a function of the center of mass energy compared to theoretical calculations based on NLO QCD and on NLO QCD complemented with NNLL resummation.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of ATLAS measurements of the single top production cross-sections in the t-channel as a function of the center of mass energy compared to a theoretical calculation based on NLO QCD.
PDF File Previous Version | |

Summary of the ATLAS and CMS Collaboration measurements of the single top production cross-sections in the t-channel at 8 TeV. The measurements are compared to a theoretical calculation based on NLO QCD computed assuming a top mass of 172.5 GeV.
PDF File Previous Version | |

Summary of measurements of the single top production cross-sections in the Wt-channel as a function of the center of mass energy compared to a theoretical calculation based on NLO QCD complemented with NNLL resummation.
PDF File Previous Version | |

Cross-section measurements for the associated production of a top quark and a W boson performed by ATLAS and CMS, and combined result compared with the NLO+NNLL prediction (gray bands). The uncertainties in the theoretical prediction are represented by dark and light gray bands for renormalisation/factorisation scale and PDF (evaluated using MSTW2008), respectively.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of the ATLAS and CMS extractions of the CKM matrix element Vtb from single top quark measurements. For each result,
the contribution to the total uncertainty originating from the uncertainty on the theoretical prediction for
the single top production cross-section is shown along with the uncertainty originating from the experimental measurement of the cross-section.
Status of figure: May 2018 (LHCtopWG meeting)
PDF File Previous Version | |

Summary of the ATLAS measurements of R_{t}, the ratio of the t-channel top-quark production cross-section to the t-channel anti-top-quark production cross-section. The data measurements are compared to NLO QCD calculations using the CT14, NNPDF 3.0 and MMHT2014 PDF sets. The coloured bands represent the uncertainties on the theoretical predictions (scale and PDF uncertainties).
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of the ATLAS measurements of R_{t}, the ratio of the t-channel top-quark production cross-section to the t-channel anti-top-quark production cross-section. The data measurements are compared to NLO QCD calculations using the ABM, HERAPDF 2.0 and JR14 PDF sets. The coloured bands represent the uncertainties on the theoretical predictions (scale and PDF uncertainties).
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

top properties plots :

Context | Preview |
---|---|

Summary of the current 95% confidence level observed limits on the branching ratios of the top quark decays via flavour changing neutral currents to a quark and a neutral boson t->Xq (X=g, Z, γ or H; q=u or c) by the ATLAS and CMS Collaborations compared to several new physics models.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of the current 95% confidence level observed limits on the branching ratios of the top quark decays via flavour changing neutral currents to an up quark and a neutral boson t->Xu (X=g, Z, γ or H). The coloured lines represent the results from HERA (the most stringent limits between the ones obtained by the H1 and ZEUS collaborations, in brown), LEP (combined ALEPH, DELPHI, L3 and OPAL collaborations result, in green), TEVATRON (the most stringent limits between the ones obtained by the CDF and D0 collaborations, in grey).
The yellow area represents the region excluded by the ATLAS and CMS Collaborations.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of the current 95% confidence level observed limits on the branching ratios of the top quark decays via flavour changing neutral currents to a charm quark and a neutral boson t->Xc (X=g, Z, γ or H). The coloured lines represent the results from HERA (the most stringent limits between the ones obtained by the H1 and ZEUS collaborations, in brown), LEP (combined ALEPH, DELPHI, L3 and OPAL collaborations result, in green), TEVATRON (the most stringent limits between the ones obtained by the CDF and D0 collaborations, in grey).
The yellow area represents the region excluded by the ATLAS and the CMS Collaborations.
Status of figure: September 2018 (Top2018)
PDF File Previous Version | |

Summary of the W boson helicity fraction measurements from ATLAS and CMS compared to the theory predictions. The uncertainty on the theory predictions is shown by the width of the green band.
Status of figure: Nov 2017 (LHCtopWG)
PDF File Previous Version | |

Summary of the charge asymmetry measurements on ATLAS and CMS at 8 TeV showing both inclusive measurements and the measurement using boosted events which is restricted to $M_{t\bar{t}}>0.75$ TeV and $|\Delta |y||<2$, compared to the respective theory predictions. The uncertainty on the theory predictions is shown but is very small.
Status of figure: September 2017 (TOP 2017), from the ATLAS+CMS combination paper
PDF File Previous Version | |

Summary of the charge asymmetry measurements on ATLAS and CMS at 7 TeV showing both the ttbar-based and lepton-based asymmetry measurements, compared to the respective theory predictions. The uncertainty on the theory predictions is shown but is very small.
Status of figure: September 2015 (Top 2015)
PDF File Previous Version | |

top mass plots :

Context | Preview |
---|---|

general plots :

Context | Preview |
---|---|

Summary of the measurements of the top quark pole mass, compared to direct measurements. The NNLO+NNLL measurements are published in Eur. Phys. J. C 74 (2014) 3109. The tt̄+1 jet (7 TeV) is published in JHEP 10 (2015) 121, the tt̄+1 jet (8 TeV) is available at arXiv:1905.02302 (2019, submitted to JHEP) and the tt̄ leptonic differential, 8 TeV, is published in Eur. Phys. J. C 77 (2017) 804. The direct reconstruction is published in Eur. Phys. J. C 79 (2019) 290. PDF File Previous Version | |

Summary of the latest ATLAS direct and indirect mtop measurements. Only results by November 2018 are included. The results are compared with the ATLAS mtop combination. For each measurement, the statistical uncertainty, the jet scale factor (JSF) and b-jet scale factor (bJSF) contributions (when applicable) as well as the sum of the remaining uncertainties are reported separately. The JSF, bJSF contributions are statistical in nature and apply to analyses performing in-situ (top quark pair base) jet energy calibration procedures. PDF File Previous Version | |

Summary of the latest ATLAS direct and indirect mtop measurements. Only results by November 2018 are included. The results are compared to the ATLAS, Tevatron and Tevatron+LHC mtop combinations. For each measurement, the statistical uncertainty, the jet scale factor (JSF) and b-jet scale factor (bJSF) contributions (when applicable) as well as the sum of the remaining uncertainties are reported separately. The JSF, bJSF contributions are statistical in nature and apply to analyses performing in-situ (top quark pair base) jet energy calibration procedures.
PDF File Previous Version | |

Summary of the ATLAS direct and indirect mtop measurements. Only results by November 2018 are included. The figure shows the latest results, as well as previous results that are now superseeded. The results are compared with the ATLAS, Tevatron and Tevatron+LHC mtop combinations. For each measurement, the statistical uncertainty, the jet scale factor (JSF) and b-jet scale factor (bJSF) contributions (when applicable) as well as the sum of the remaining uncertainties are reported separately. The JSF, bJSF contributions are statistical in nature and apply to analyses performing in-situ (top quark pair base) jet energy calibration procedures. PDF File Previous Version | |

Summary of the ATLAS and CMS direct mtop measurements. The results are compared with the LHC and Tevatron+LHC mtop combinations. For each measurement, the statistical uncertainty, the jet scale factor (JSF) and b-jet scale factor (bJSF) contributions (when applicable) as well as the sum of the remaining uncertainties are reported separately. The JSF, bJSF contributions are statistical in nature and apply to analyses performing in-situ (top quark pair base) jet energy calibration procedures. PDF File Previous Version | |

Selections within a section row are combined with a logical OR, while selections among different section rows are combined with a logical AND.