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Measurement of the total and differential cross-sections of $t\bar{t}W$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Measurements of inclusive and differential production cross-sections of a top-quark-top-antiquark pair in association with a $W$ boson ($t\bar{t}W$) are presented. They are performed by targeting final states with two same-sign or three isolated leptons (electrons or muons) and are based on $\sqrt{s}=13$ TeV proton-proton collision data with an integrated luminosity of 140 fb$^{-1}$, recorded from 2015 to 2018 with the ATLAS detector at the Large Hadron Collider. The inclusive $t\bar{t}W$ production cross-section is measured to be $880 \pm 80$ fb, compared to a reference theoretical prediction of $745 \pm 50\,\textrm{(scale)} \pm 13\,\textrm{(2-loop approx.)} \pm 19\,(\textrm{PDF}, \alpha_s)$ fb. Differential cross-section measurements characterise this process in detail for the first time. Several particle-level observables are compared with a variety of theoretical predictions, which generally agree well with the normalised differential cross-section results. Additionally, the relative charge asymmetry of $t\bar{t}W^{+}$ and $t\bar{t}W^{-}$ is measured inclusively to be $A_{\mathrm{C}}^{\mathrm{rel}} = 0.33 \pm 0.05$, in very good agreement with the theoretical prediction of $0.322 \pm 0.003\,\mathrm{(scale)} \pm 0.007\,\mathrm{(PDF)}$, as well as differentially.

10 January 2024

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Figures

Figure 01a


Illustrative Feynman diagrams for the dominant production modes of ttW: (a) the LO contribution (ααs2), (b) a real emission diagram from the NLO QCD contribution (ααs3), (c) the tree-level EWK contribution (α3), and (d) a representative diagram of the combined NLO QCD and EWK contributions (α3αs). The pink circles correspond to QCD couplings and the blue circles correspond to EWK couplings.

png (16kB)  pdf (25kB) 

Figure 01b


Illustrative Feynman diagrams for the dominant production modes of ttW: (a) the LO contribution (ααs2), (b) a real emission diagram from the NLO QCD contribution (ααs3), (c) the tree-level EWK contribution (α3), and (d) a representative diagram of the combined NLO QCD and EWK contributions (α3αs). The pink circles correspond to QCD couplings and the blue circles correspond to EWK couplings.

png (18kB)  pdf (26kB) 

Figure 01c


Illustrative Feynman diagrams for the dominant production modes of ttW: (a) the LO contribution (ααs2), (b) a real emission diagram from the NLO QCD contribution (ααs3), (c) the tree-level EWK contribution (α3), and (d) a representative diagram of the combined NLO QCD and EWK contributions (α3αs). The pink circles correspond to QCD couplings and the blue circles correspond to EWK couplings.

png (16kB)  pdf (32kB) 

Figure 01d


Illustrative Feynman diagrams for the dominant production modes of ttW: (a) the LO contribution (ααs2), (b) a real emission diagram from the NLO QCD contribution (ααs3), (c) the tree-level EWK contribution (α3), and (d) a representative diagram of the combined NLO QCD and EWK contributions (α3αs). The pink circles correspond to QCD couplings and the blue circles correspond to EWK couplings.

png (17kB)  pdf (26kB) 

Figure 02a


Comparison between data and the signal-plus-background prediction for (a) the total yield in the 3ℓVV CR and (b) the distribution of the b-jet multiplicity in the 3ℓttZ CR after the VV jet multiplicity correction. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Bkg.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total prediction ("Pred.") is shown in the lower panel, separately for the post-fit prediction (black points) and pre-fit background (dashed blue line). The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band. The "Other" background contribution is dominated by tZ and WtZ production.

png (115kB)  pdf (91kB) 

Figure 02b


Comparison between data and the signal-plus-background prediction for (a) the total yield in the 3ℓVV CR and (b) the distribution of the b-jet multiplicity in the 3ℓttZ CR after the VV jet multiplicity correction. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Bkg.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total prediction ("Pred.") is shown in the lower panel, separately for the post-fit prediction (black points) and pre-fit background (dashed blue line). The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band. The "Other" background contribution is dominated by tZ and WtZ production.

png (129kB)  pdf (108kB) 

Figure 03a


Comparison between data and the signal-plus-background prediction for the distribution of the transverse momentum of the sub-leading lepton (pTℓ 1) in (a) the 2ℓtt(e)TMex CR and (b) the 2ℓtt(μ)TMex CR. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Bkg.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total prediction ("Pred.") is shown in the lower panel, separately for the post-fit prediction (black points) and pre-fit background (dashed blue line). The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band. The last bin in each figure contains the overflow.

png (140kB)  pdf (93kB) 

Figure 03b


Comparison between data and the signal-plus-background prediction for the distribution of the transverse momentum of the sub-leading lepton (pTℓ 1) in (a) the 2ℓtt(e)TMex CR and (b) the 2ℓtt(μ)TMex CR. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Bkg.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total prediction ("Pred.") is shown in the lower panel, separately for the post-fit prediction (black points) and pre-fit background (dashed blue line). The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band. The last bin in each figure contains the overflow.

png (136kB)  pdf (94kB) 

Figure 04


Comparison between data and the signal-plus-background prediction for the event yields in the ten control region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Bkg.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total prediction ("Pred.") is shown in the lower panel, separately for the post-fit prediction (black points) and pre-fit background (dashed blue line). The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (117kB)  pdf (111kB) 

Figure 05a


Comparison between data and the signal-plus-background prediction for the event yields in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 3ℓ+ and (d) 3ℓ– signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel. The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (129kB)  pdf (81kB) 

Figure 05b


Comparison between data and the signal-plus-background prediction for the event yields in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 3ℓ+ and (d) 3ℓ– signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel. The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (128kB)  pdf (80kB) 

Figure 05c


Comparison between data and the signal-plus-background prediction for the event yields in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 3ℓ+ and (d) 3ℓ– signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel. The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (119kB)  pdf (75kB) 

Figure 05d


Comparison between data and the signal-plus-background prediction for the event yields in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 3ℓ+ and (d) 3ℓ– signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel. The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (125kB)  pdf (75kB) 

Figure 06a


Comparison of (a) the measured inclusive ttW cross-section and (b) the ttW+/ttW- cross-section ratio with theoretical predictions from SHERPA, the MadGraph5+Pythia 8 FxFx prescription including EWK corrections from Ref. [27], the NLO+NNLL calculation from Ref. [20], and the NNLO calculation from Ref. [15], and also the measurement from CMS [9]. The theoretical uncertainty in ttW+/ttW- is calculated assuming scale variations are fully correlated between ttW+ and ttW-.

png (137kB)  pdf (46kB) 

Figure 06b


Comparison of (a) the measured inclusive ttW cross-section and (b) the ttW+/ttW- cross-section ratio with theoretical predictions from SHERPA, the MadGraph5+Pythia 8 FxFx prescription including EWK corrections from Ref. [27], the NLO+NNLL calculation from Ref. [20], and the NNLO calculation from Ref. [15], and also the measurement from CMS [9]. The theoretical uncertainty in ttW+/ttW- is calculated assuming scale variations are fully correlated between ttW+ and ttW-.

png (120kB)  pdf (45kB) 

Figure 07


Two-dimensional likelihood scan of the ttW+ and ttW- cross-sections. The black cross indicates the best-fit point and the green and lilac markers show the SM predictions from Refs. [27] and [15], respectively. The blue dashed and solid lines correspond to the 68% and 95% confidence interval contours, respectively.

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Figure 08a


Ranking of the nuisance parameters and background normalisation factors included in the fit according to their impact on (a) the ttW cross-section, σ(ttW), and (b) R(ttW). In both (a) and (b), only the 15 nuisance parameters with the largest impacts are shown. The empty (solid) blue rectangles illustrate the pre-fit (post-fit) impacts on the parameter of interest, σ(ttW) in (a) and R(ttW) in (b), corresponding to the top axis. The pre-fit (post-fit) impact of each nuisance parameter, Δσ(ttW) in (a) and Δ R(ttW) in (b), is calculated as the difference in the fitted value of (a) σ(ttW) or (b) R(ttW) between the nominal fit and the fit when fixing the corresponding nuisance parameter to hatθ ± Δθ (hatθ ± Δhatθ), where hatθ is the best-fit value of the nuisance parameter and Δθ (Δhatθ) is its pre-fit (post-fit) uncertainty. The black points show the pulls of the nuisance parameters relative to zero, θ0=0. These pulls and their relative post-fit errors, Δhatθ/Δθ, refer to the bottom axis. The background normalisation factors λ (red points) are pulled relative to one, θ0=1. The fitted values and their post-fit errors refer to the bottom axis. The systematic uncertainties with "[T]" affect only the "tight" leptons.

png (111kB)  pdf (127kB) 

Figure 08b


Ranking of the nuisance parameters and background normalisation factors included in the fit according to their impact on (a) the ttW cross-section, σ(ttW), and (b) R(ttW). In both (a) and (b), only the 15 nuisance parameters with the largest impacts are shown. The empty (solid) blue rectangles illustrate the pre-fit (post-fit) impacts on the parameter of interest, σ(ttW) in (a) and R(ttW) in (b), corresponding to the top axis. The pre-fit (post-fit) impact of each nuisance parameter, Δσ(ttW) in (a) and Δ R(ttW) in (b), is calculated as the difference in the fitted value of (a) σ(ttW) or (b) R(ttW) between the nominal fit and the fit when fixing the corresponding nuisance parameter to hatθ ± Δθ (hatθ ± Δhatθ), where hatθ is the best-fit value of the nuisance parameter and Δθ (Δhatθ) is its pre-fit (post-fit) uncertainty. The black points show the pulls of the nuisance parameters relative to zero, θ0=0. These pulls and their relative post-fit errors, Δhatθ/Δθ, refer to the bottom axis. The background normalisation factors λ (red points) are pulled relative to one, θ0=1. The fitted values and their post-fit errors refer to the bottom axis. The systematic uncertainties with "[T]" affect only the "tight" leptons.

png (116kB)  pdf (144kB) 

Figure 09a


The (a) normalised migration matrix and (b) efficiency/acceptance corrections for Njets calculated in Sherpa 2.2.10 with EWK corrections. The 3ℓ regions are split according to the number of OS-SF lepton pairs, shown in brackets. The highest jet-multiplicity bin in each subregion is inclusive.

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Figure 09b


The (a) normalised migration matrix and (b) efficiency/acceptance corrections for Njets calculated in Sherpa 2.2.10 with EWK corrections. The 3ℓ regions are split according to the number of OS-SF lepton pairs, shown in brackets. The highest jet-multiplicity bin in each subregion is inclusive.

png (45kB)  pdf (18kB) 

Figure 10a


Signal region datasets for the Njets unfolding in (a) the pre-fit case and (b) the post-fit case. The 3ℓ regions are split according to the number of OS-SF lepton pairs, shown in brackets. The highest jet-multiplicity bin in each subregion is inclusive. The signal and background contributions before and after the likelihood fit to data under the signal-plus-background hypothesis are shown as filled histograms. The ratio of the data to the total pre-fit and post-fit predictions ("Pred.") is shown in the lower panel. The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band. The blue triangles indicate points that are outside the vertical range of the figure.

png (138kB)  pdf (101kB) 

Figure 10b


Signal region datasets for the Njets unfolding in (a) the pre-fit case and (b) the post-fit case. The 3ℓ regions are split according to the number of OS-SF lepton pairs, shown in brackets. The highest jet-multiplicity bin in each subregion is inclusive. The signal and background contributions before and after the likelihood fit to data under the signal-plus-background hypothesis are shown as filled histograms. The ratio of the data to the total pre-fit and post-fit predictions ("Pred.") is shown in the lower panel. The combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band. The blue triangles indicate points that are outside the vertical range of the figure.

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Figure 11a


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of jet multiplicity. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (381kB)  pdf (240kB) 

Figure 11b


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of jet multiplicity. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (210kB)  pdf (109kB) 

Figure 11c


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of jet multiplicity. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

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Figure 12a


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of HT,jets. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (410kB)  pdf (260kB) 

Figure 12b


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of HT,jets. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (219kB)  pdf (114kB) 

Figure 12c


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of HT,jets. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (555kB)  pdf (220kB) 

Figure 13a


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of HT,lep. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (456kB)  pdf (311kB) 

Figure 13b


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of HT,lep. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (230kB)  pdf (123kB) 

Figure 13c


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of HT,lep. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (651kB)  pdf (277kB) 

Figure 14a


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of ΔRlb, lead. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (451kB)  pdf (3MB) 

Figure 14b


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of ΔRlb, lead. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (233kB)  pdf (126kB) 

Figure 14c


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of ΔRlb, lead. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (624kB)  pdf (274kB) 

Figure 15a


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of |Δφll, SS|. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (462kB)  pdf (318kB) 

Figure 15b


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of |Δφll, SS|. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (227kB)  pdf (123kB) 

Figure 15c


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of |Δφll, SS|. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (634kB)  pdf (277kB) 

Figure 16a


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of |Δηll, SS|. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (2MB)  pdf (366kB) 

Figure 16b


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of |Δηll, SS|. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (224kB)  pdf (891kB) 

Figure 16c


Unfolded distributions of (a) the lepton-charge-combined absolute cross-section, the normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton-charge-split absolute and normalised cross-sections, as a function of |Δηll, SS|. The coloured markers overlaid upon the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

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Tables

Table 01


Summary of theoretical predictions with NNLO precision in the strong coupling [15] and using FxFx NLO multijet merging [27], both including NLO EWK corrections. The first uncertainty is due to variations of the chosen renormalisation and factorisation scales. Where there is a second contribution to the uncertainty, this corresponds to the approximation used in the 2-loop calculation. Uncertainties due to the choice of PDF and αs are omitted.

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Table 02


The configurations used to generate events from signal and background processes. The samples used to estimate the systematic uncertainties are indicated in parentheses and in grey.

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Table 03


Description of the loose inclusive (L), medium inclusive (M), medium exclusive (Mex), and tight (T) lepton definitions. The electron e* is required to fulfil, in addition to the corresponding lepton definition requirements, those corresponding to an internal or material conversion candidate.

png (26kB)  pdf (79kB) 

Table 04


Event selection summary in the signal regions. Leptons are ordered in pT in the 2ℓSS regions. In the 3ℓ regions the lepton with opposite-sign charge is called the first lepton, followed by the two same-sign leptons. In the lepton selection, T and L stand for tight and loose lepton definitions (see Table 3). In the b-jet multiplicity categorisation, Nb-jets is defined to be 2 or more if the events contain at least two bloose jets, or 1 if the events contain exactly one btight jet. For each of the 2ℓSS and 3ℓ signal regions in the inclusive and differential measurements, each categorisation split affects all regions above.

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Table 05


Event selection summary in the control regions. The lepton types L, M, Mex, and T correspond to the loose inclusive, medium inclusive, medium exclusive, and tight lepton definitions, as described in Table 3. The notation e* is used to denote material conversion or internal conversion candidates, as described in Section 4.

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Table 06


Definition of objects and selections for fiducial regions.

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Table 07


Summary of observed and predicted yields in the four signal region categories. The background prediction is shown after the combined likelihood fit to data under the signal-plus-background hypothesis across all control region and signal region categories. The quoted uncertainties consider all statistical and systematic uncertainties after the fit to data. The uncertainty on the total yield can be smaller than the quadratic sum of uncertainties of the individual contributions due to the anti-correlations resulting from the likelihood fit.

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Table 08


Summary of observed and predicted yields in the 2ℓSS control region categories. The background prediction is shown after the combined likelihood fit to data under the signal-plus-background hypothesis across all control region and signal region categories. The quoted uncertainties consider all statistical and systematic uncertainties after the fit to data. The uncertainty on the total yield can be smaller than the quadratic sum of uncertainties of the individual contributions due to the anti-correlations resulting from the likelihood fit.

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Table 09


Summary of observed and predicted yields in the 3ℓ control region categories. The background prediction is shown after the combined likelihood fit to data under the signal-plus-background hypothesis across all control region and signal region categories.

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Table 10


The impact of the main sources of uncertainty on the measured quantities. The impact of each uncertainty on σ(tt̄W) is assessed by fixing the relevant fit parameters for a given uncertainty and re-fitting to data. The reduction in the total uncertainty in this modified fit gives the quoted impact. Different individual components used in the fit are combined into categories. The leading contributions to the prompt-lepton background normalisation uncertainty are the tt̄H and tt̄tt̄ normalisation uncertainties. In the fourth row, "Fakes" stands for non-prompt leptons.

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Table 11


Definition of observables measured.

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Table 12


Choice of regularisation parameter τ used for each observable and region.

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Table 13


χ2 and p-values calculated for unfolded normalised cross-section distributions in the 2ℓSS region.

png (24kB)  pdf (65kB) 

Table 14


χ2 and p-values calculated for unfolded normalised cross-section distributions in the 3ℓ region.

png (24kB)  pdf (65kB) 

Table 15


χ2 and p-values calculated for unfolded asymmetry distributions in the 2ℓSS region.

png (26kB)  pdf (65kB) 

Table 16


χ2 and p-values calculated for unfolded asymmetry distributions in the 3ℓ region.

png (22kB)  pdf (66kB) 

Auxiliary material

Figure 01a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for HT,jets calculated in Sherpa 2.2.10 with EWK corrections.

png (94kB)  pdf (24kB) 

Figure 01b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for HT,jets calculated in SHERPA 2.2.10 with EWK corrections.

png (49kB)  pdf (18kB) 

Figure 02a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for HT,lep calculated in Sherpa 2.2.10 with EWK corrections.

png (94kB)  pdf (24kB) 

Figure 02b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for HT,lep calculated in Sherpa 2.2.10 with EWK corrections.

png (49kB)  pdf (19kB) 

Figure 03a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for ΔRlb, lead calculated in Sherpa 2.2.10 with EWK corrections.

png (90kB)  pdf (26kB) 

Figure 03b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for ΔRlb, lead calculated in Sherpa 2.2.10 with EWK corrections.

png (51kB)  pdf (19kB) 

Figure 04a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for |Δφll, SS| calculated in Sherpa 2.2.10 with EWK corrections.

png (91kB)  pdf (22kB) 

Figure 04b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for |Δφll, SS| calculated in Sherpa 2.2.10 with EWK corrections.

png (52kB)  pdf (20kB) 

Figure 05a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for |Δηll, SS| calculated in Sherpa 2.2.10 with EWK corrections.

png (86kB)  pdf (23kB) 

Figure 05b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for |Δηll, SS| calculated in Sherpa 2.2.10 with EWK corrections.

png (51kB)  pdf (20kB) 

Figure 06a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for Mlb, lead calculated in Sherpa 2.2.10 with EWK corrections.

png (102kB)  pdf (26kB) 

Figure 06b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for Mlb, lead calculated in Sherpa 2.2.10 with EWK corrections.

png (51kB)  pdf (19kB) 

Figure 07a


(a) Normalised migration matrix and (b) efficiency/acceptance correction for Mll, SS calculated in Sherpa 2.2.10 with EWK corrections.

png (99kB)  pdf (23kB) 

Figure 07b


(a) Normalised migration matrix and (b) efficiency/acceptance correction for Mll, SS calculated in Sherpa 2.2.10 with EWK corrections.

png (52kB)  pdf (19kB) 

Figure 08a


Unfolded distributions of (a) the lepton charge combined absolute cross-section, normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton charge split absolute and normalised cross-sections, as a function of Mlb, lead. The coloured markers overlaid upon the the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (444kB)  pdf (288kB) 

Figure 08b


Unfolded distributions of (a) the lepton charge combined absolute cross-section, normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton charge split absolute and normalised cross-sections, as a function of Mlb, lead. The coloured markers overlaid upon the the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (227kB)  pdf (116kB) 

Figure 08c


Unfolded distributions of (a) the lepton charge combined absolute cross-section, normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton charge split absolute and normalised cross-sections, as a function of Mlb, lead. The coloured markers overlaid upon the the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (601kB)  pdf (249kB) 

Figure 09a


Unfolded distributions of (a) the lepton charge combined absolute cross-section, normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton charge split absolute and normalised cross-sections, as a function of Mll, SS. The coloured markers overlaid upon the the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (480kB)  pdf (320kB) 

Figure 09b


Unfolded distributions of (a) the lepton charge combined absolute cross-section, normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton charge split absolute and normalised cross-sections, as a function of Mll, SS. The coloured markers overlaid upon the the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (227kB)  pdf (121kB) 

Figure 09c


Unfolded distributions of (a) the lepton charge combined absolute cross-section, normalised cross-section and ACrel, (b) the corresponding uncertainty breakdowns, and (c) unfolded distributions of the lepton charge split absolute and normalised cross-sections, as a function of Mll, SS. The coloured markers overlaid upon the the cross-section measurements show different theoretical predictions. The breakdown of statistical-only uncertainties is shown in light grey in the bottom panels, and combined statistical and systematic uncertainties are shown in dark grey. The dotted/dashed/full lines in (b) show the relative contributions of grouped sources of systematic uncertainty. The triangles indicate points that are outside the vertical range of the figure.

png (648kB)  pdf (275kB) 

Figure 10a


Comparison between data and the signal plus background prediction for the Njets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (129kB)  pdf (75kB) 

Figure 10b


Comparison between data and the signal plus background prediction for the Njets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (128kB)  pdf (75kB) 

Figure 10c


Comparison between data and the signal plus background prediction for the Njets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (128kB)  pdf (75kB) 

Figure 10d


Comparison between data and the signal plus background prediction for the Njets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (135kB)  pdf (75kB) 

Figure 10e


Comparison between data and the signal plus background prediction for the Njets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (132kB)  pdf (75kB) 

Figure 10f


Comparison between data and the signal plus background prediction for the Njets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (131kB)  pdf (75kB) 

Figure 11a


Comparison between data and the signal plus background prediction for the Nb-jets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (118kB)  pdf (75kB) 

Figure 11b


Comparison between data and the signal plus background prediction for the Nb-jets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (115kB)  pdf (74kB) 

Figure 11c


Comparison between data and the signal plus background prediction for the Nb-jets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (116kB)  pdf (74kB) 

Figure 11d


Comparison between data and the signal plus background prediction for the Nb-jets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (129kB)  pdf (74kB) 

Figure 11e


Comparison between data and the signal plus background prediction for the Nb-jets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (121kB)  pdf (74kB) 

Figure 11f


Comparison between data and the signal plus background prediction for the Nb-jets distribution in the (a) 2ℓSS++, (b) 2ℓSS– –, (c) 2ℓSS, (d) 3ℓ+, (e) 3ℓ– and (f) 3ℓ  signal region categories. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (134kB)  pdf (75kB) 

Figure 12a


Comparison between data and the signal plus background prediction for the (a) ETmiss, (b) leading jet pT, (c) leading lepton pT, and (d) sub-leading lepton pT distributions in the 2ℓSS signal region category, as well as for the (e) M3ℓ distribution in the 3ℓ signal region category. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (151kB)  pdf (96kB) 

Figure 12b


Comparison between data and the signal plus background prediction for the (a) ETmiss, (b) leading jet pT, (c) leading lepton pT, and (d) sub-leading lepton pT distributions in the 2ℓSS signal region category, as well as for the (e) M3ℓ distribution in the 3ℓ signal region category. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (156kB)  pdf (97kB) 

Figure 12c


Comparison between data and the signal plus background prediction for the (a) ETmiss, (b) leading jet pT, (c) leading lepton pT, and (d) sub-leading lepton pT distributions in the 2ℓSS signal region category, as well as for the (e) M3ℓ distribution in the 3ℓ signal region category. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (141kB)  pdf (95kB) 

Figure 12d


Comparison between data and the signal plus background prediction for the (a) ETmiss, (b) leading jet pT, (c) leading lepton pT, and (d) sub-leading lepton pT distributions in the 2ℓSS signal region category, as well as for the (e) M3ℓ distribution in the 3ℓ signal region category. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (142kB)  pdf (96kB) 

Figure 12e


Comparison between data and the signal plus background prediction for the (a) ETmiss, (b) leading jet pT, (c) leading lepton pT, and (d) sub-leading lepton pT distributions in the 2ℓSS signal region category, as well as for the (e) M3ℓ distribution in the 3ℓ signal region category. The signal and background contributions after the likelihood fit to data ("Post-Fit") under the signal-plus-background hypothesis are shown as filled histograms. The total signal-plus-background prediction before the likelihood fit to data ("Pre-Fit Pred.") is shown as a dashed blue histogram in the upper panel. The ratio of the data to the total post-fit prediction ("Pred.") is shown in the lower panel, separately for post-fit (black points) and pre-fit (dashed blue line) predictions. The size of the combined statistical and systematic uncertainty in the prediction is indicated by the blue hatched band.

png (137kB)  pdf (92kB) 

Table 01


Definition of additional observables measured.

png (8kB)  pdf (40kB) 

Table 02


Choice of regularisation parameter τ used for Mlb, lead and Mll, SS in each region.

png (6kB)  pdf (50kB) 

Table 03


χ2 and p-values calculated for unfolded normalised cross-section distributions in the 2ℓSS region.

png (14kB)  pdf (46kB) 

Table 04


χ2 and p-values calculated for unfolded normalised cross-section distributions in the 3ℓ region.

png (13kB)  pdf (46kB) 

Table 05


χ2 and p-values calculated for unfolded asymmetry distributions in the 2ℓSS region.

png (14kB)  pdf (45kB) 

Table 06


χ2 and p-values calculated for unfolded asymmetry distributions in the 3ℓ region.

png (12kB)  pdf (47kB) 

Table 07


χ2 and p-values calculated for unfolded absolute cross-section distributions in the 2ℓSS region.

png (31kB)  pdf (66kB) 

Table 08


χ2 and p-values calculated for unfolded absolute cross-section distributions in the 3ℓ region.

png (29kB)  pdf (66kB)