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| CMS-PAS-SMP-18-002 | ||
| Measurements of the $\mathrm{pp}\to\mathrm{WZ}$ inclusive and differential production cross section and constraints on charged anomalous triple gauge couplings at $\sqrt{s} = $ 13 TeV. | ||
| CMS Collaboration | ||
| July 2018 | ||
| Abstract: The WZ production cross section is measured in proton-proton collisions using 35.9 fb$^{-1}$ of data collected with the CMS detector. An estimate of the inclusive cross section yields a result of $\sigma_{\textrm{tot}}(\mathrm{pp} \rightarrow \mathrm{WZ}) = $ 48.09 $^{+1.00}_{-0.96}$ (stat) $^{+0.44}_{-0.37}$ (theo) $^{+2.39}_{-2.17}$ (syst) $\pm$ 1.39 (lumi) pb, for a total uncertainty of $-2.78$ and $+2.98$ pb. Fiducial and charge asymmetry measurements are provided. Differential cross section measurements are also presented with respect to three variables: the Z boson $p_{\mathrm{T}}$, the leading jet $p_{\mathrm{T}}$, and the $M_{\mathrm{WZ}}$ variable, defined as the invariant mass of the system composed of the three leptons and the missing transverse momentum. Differential measurements with respect to the W boson $p_{\mathrm{T}}$, split by charge, are also shown. Results are consistent with standard model predictions, favouring next-to-next-to-leading-order calculations. Constraints on anomalous triple gauge couplings are derived via a binned maximum likelihood fit to the $M_{\mathrm{WZ}}$ variable. | ||
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Links:
CDS record (PDF) ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, JHEP 04 (2019) 122. The superseded preliminary plots can be found here. |
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| Figures | |
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Figure 1:
Feynman diagrams for WZ production at leading order in proton-proton collisions. The contributions from the s-channel (left), t-channel (middle), and u-channel (right) are presented. The contribution from s-channel proceeds through TGC. |
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Figure 1-a:
Feynman diagrams for WZ production at leading order in proton-proton collisions. The contributions from the s-channel (left), t-channel (middle), and u-channel (right) are presented. The contribution from s-channel proceeds through TGC. |
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Figure 1-b:
Feynman diagrams for WZ production at leading order in proton-proton collisions. The contributions from the s-channel (left), t-channel (middle), and u-channel (right) are presented. The contribution from s-channel proceeds through TGC. |
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Figure 1-c:
Feynman diagrams for WZ production at leading order in proton-proton collisions. The contributions from the s-channel (left), t-channel (middle), and u-channel (right) are presented. The contribution from s-channel proceeds through TGC. |
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Figure 2:
Distribution of key observables in the signal region: invariant mass of the lepton pair assigned to the Z boson (top left), invariant mass of the three lepton system (top right), missing transverse momentum (bottom left), and momentum of the leading lepton assigned to the Z boson. Each of the distributions is represented applying the signal region requirements minus the one directly related to itself so the effect of its separation can be easily observed. The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty at their values after the signal extraction fit. |
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Figure 2-a:
Distribution of key observables in the signal region: invariant mass of the lepton pair assigned to the Z boson (top left), invariant mass of the three lepton system (top right), missing transverse momentum (bottom left), and momentum of the leading lepton assigned to the Z boson. Each of the distributions is represented applying the signal region requirements minus the one directly related to itself so the effect of its separation can be easily observed. The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty at their values after the signal extraction fit. |
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Figure 2-b:
Distribution of key observables in the signal region: invariant mass of the lepton pair assigned to the Z boson (top left), invariant mass of the three lepton system (top right), missing transverse momentum (bottom left), and momentum of the leading lepton assigned to the Z boson. Each of the distributions is represented applying the signal region requirements minus the one directly related to itself so the effect of its separation can be easily observed. The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty at their values after the signal extraction fit. |
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Figure 2-c:
Distribution of key observables in the signal region: invariant mass of the lepton pair assigned to the Z boson (top left), invariant mass of the three lepton system (top right), missing transverse momentum (bottom left), and momentum of the leading lepton assigned to the Z boson. Each of the distributions is represented applying the signal region requirements minus the one directly related to itself so the effect of its separation can be easily observed. The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty at their values after the signal extraction fit. |
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Figure 2-d:
Distribution of key observables in the signal region: invariant mass of the lepton pair assigned to the Z boson (top left), invariant mass of the three lepton system (top right), missing transverse momentum (bottom left), and momentum of the leading lepton assigned to the Z boson. Each of the distributions is represented applying the signal region requirements minus the one directly related to itself so the effect of its separation can be easily observed. The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty at their values after the signal extraction fit. |
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Figure 3:
Distribution of key observables of the analysis in the ZZ control region: flavour composition of the three leading leptons (top left), invariant mass of the three leptons plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it, and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 3-a:
Distribution of key observables of the analysis in the ZZ control region: flavour composition of the three leading leptons (top left), invariant mass of the three leptons plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it, and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 3-b:
Distribution of key observables of the analysis in the ZZ control region: flavour composition of the three leading leptons (top left), invariant mass of the three leptons plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it, and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 3-c:
Distribution of key observables of the analysis in the ZZ control region: flavour composition of the three leading leptons (top left), invariant mass of the three leptons plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it, and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 3-d:
Distribution of key observables of the analysis in the ZZ control region: flavour composition of the three leading leptons (top left), invariant mass of the three leptons plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it, and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 4:
Distribution of key observables of the analysis in the top enriched control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 4-a:
Distribution of key observables of the analysis in the top enriched control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 4-b:
Distribution of key observables of the analysis in the top enriched control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 4-c:
Distribution of key observables of the analysis in the top enriched control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 4-d:
Distribution of key observables of the analysis in the top enriched control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 5:
Distribution of key observables of the analysis in the conversion control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 5-a:
Distribution of key observables of the analysis in the conversion control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 5-b:
Distribution of key observables of the analysis in the conversion control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 5-c:
Distribution of key observables of the analysis in the conversion control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 5-d:
Distribution of key observables of the analysis in the conversion control region: flavour composition of the three leading leptons (top left), invariant mass of the three lepton plus missing transverse momentum (top right), transverse momentum of the Z boson reconstructed from the ${p_{\mathrm {T}}}$ of the two leptons assigned to it and transverse momentum of the leading jet. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 6:
Distribution of expected and observed event yields in the four flavour categories used for the cross section measurement. Vertical bars on the data points include their statistical uncertainty and shaded bands over the prediction include the contributions of the different sources of uncertainty evaluated after the signal extraction fit. |
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Figure 7:
Measured ratio of cross sections for the two charge channels for each of the flavour categories and their combination. Coloured bands for each of the points include both systematic and statistical uncertainties. Shaded bands correspond to the Monte Carlo prediction from the nominal {powheg} sample and its associated uncertainty. |
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Figure 8:
Distributions of key observables in the signal region. The transverse momentum of the Z boson, estimated from the two final state leptons assigned to the Z boson, (top left), the transverse momentum of the leading jet (top right), and the mass of the WZ system, estimated as the mass of the trilepton system plus the missing transverse momentum vector (bottom). The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the MC prediction include both the statistical and the systematic uncertainties in the normalization of each of the background processes. An additional 15% uncertainty is assigned to the signal WZ process in the figures to account for the NLO/NNLO normalization differences. |
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Figure 8-a:
Distributions of key observables in the signal region. The transverse momentum of the Z boson, estimated from the two final state leptons assigned to the Z boson, (top left), the transverse momentum of the leading jet (top right), and the mass of the WZ system, estimated as the mass of the trilepton system plus the missing transverse momentum vector (bottom). The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the MC prediction include both the statistical and the systematic uncertainties in the normalization of each of the background processes. An additional 15% uncertainty is assigned to the signal WZ process in the figures to account for the NLO/NNLO normalization differences. |
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Figure 8-b:
Distributions of key observables in the signal region. The transverse momentum of the Z boson, estimated from the two final state leptons assigned to the Z boson, (top left), the transverse momentum of the leading jet (top right), and the mass of the WZ system, estimated as the mass of the trilepton system plus the missing transverse momentum vector (bottom). The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the MC prediction include both the statistical and the systematic uncertainties in the normalization of each of the background processes. An additional 15% uncertainty is assigned to the signal WZ process in the figures to account for the NLO/NNLO normalization differences. |
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Figure 8-c:
Distributions of key observables in the signal region. The transverse momentum of the Z boson, estimated from the two final state leptons assigned to the Z boson, (top left), the transverse momentum of the leading jet (top right), and the mass of the WZ system, estimated as the mass of the trilepton system plus the missing transverse momentum vector (bottom). The last bin contains the overflow. Vertical bars on the data points include their statistical uncertainty and shaded bands over the MC prediction include both the statistical and the systematic uncertainties in the normalization of each of the background processes. An additional 15% uncertainty is assigned to the signal WZ process in the figures to account for the NLO/NNLO normalization differences. |
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Figure 9:
Response matrices obtained using NLO simulated samples, for the {powheg} generator. The leading jet transverse momentum (top left), the transverse momentum of the Z boson (top right), and the mass of the WZ system (bottom) are shown. |
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Figure 9-a:
Response matrices obtained using NLO simulated samples, for the {powheg} generator. The leading jet transverse momentum (top left), the transverse momentum of the Z boson (top right), and the mass of the WZ system (bottom) are shown. |
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Figure 9-b:
Response matrices obtained using NLO simulated samples, for the {powheg} generator. The leading jet transverse momentum (top left), the transverse momentum of the Z boson (top right), and the mass of the WZ system (bottom) are shown. |
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Figure 9-c:
Response matrices obtained using NLO simulated samples, for the {powheg} generator. The leading jet transverse momentum (top left), the transverse momentum of the Z boson (top right), and the mass of the WZ system (bottom) are shown. |
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Figure 10:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13. The leading jet ${p_{\mathrm {T}}}$ (top left), Z boson ${p_{\mathrm {T}}}$ (top right), and mass of the WZ system (bottom) data distributions are unfolded at the dressed leptons level and compared with the {powheg}, MadGraph5\_aMC@NLO, and {pythia} predictions. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 10-a:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13. The leading jet ${p_{\mathrm {T}}}$ (top left), Z boson ${p_{\mathrm {T}}}$ (top right), and mass of the WZ system (bottom) data distributions are unfolded at the dressed leptons level and compared with the {powheg}, MadGraph5\_aMC@NLO, and {pythia} predictions. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 10-b:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13. The leading jet ${p_{\mathrm {T}}}$ (top left), Z boson ${p_{\mathrm {T}}}$ (top right), and mass of the WZ system (bottom) data distributions are unfolded at the dressed leptons level and compared with the {powheg}, MadGraph5\_aMC@NLO, and {pythia} predictions. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 10-c:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13. The leading jet ${p_{\mathrm {T}}}$ (top left), Z boson ${p_{\mathrm {T}}}$ (top right), and mass of the WZ system (bottom) data distributions are unfolded at the dressed leptons level and compared with the {powheg}, MadGraph5\_aMC@NLO, and {pythia} predictions. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 11:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The leading jet transverse momentum is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 11-a:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The leading jet transverse momentum is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 11-b:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The leading jet transverse momentum is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 12:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The transverse momentum of the Z boson is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 12-a:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The transverse momentum of the Z boson is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 12-b:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The transverse momentum of the Z boson is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 13:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The mass of the WZ system data distribution is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 13-a:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The mass of the WZ system data distribution is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 13-b:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The mass of the WZ system data distribution is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 14:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The W boson transverse momentum is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 14-a:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The W boson transverse momentum is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 14-b:
Results for non-regularized unfolding, area constraint, and a bias scale of 1.13 for ${\mathrm {W}}^{+}$ (left) and ${\mathrm {W}}^{-}$ (right), in the full SR. The W boson transverse momentum is unfolded at the dressed leptons level. The red band around the {powheg} prediction represents the theory uncertainty on the prediction; the effect on the unfolded data of this uncertainty, through the unfolding matrix, is included in the grey bands described in the legend. The agreement between the normalizations is forced by the choice of bias scale. |
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Figure 15:
Distributions of discriminant observables in the anomalous couplings searches. The invariant mass of the three lepton plus the missing transverse momentum system (left) and the transverse mass of the same configuration (right). The dashed lines represent the total yields that would be expected from the sum of the SM processes with the total WZ yields modified according to their correspondence to the given values of the associated anomalous coupling parameters. The SM prediction for the WZ process is obtained from the aTGC simulated sample with the anomalous couplings set to $0$. |
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Figure 15-a:
Distributions of discriminant observables in the anomalous couplings searches. The invariant mass of the three lepton plus the missing transverse momentum system (left) and the transverse mass of the same configuration (right). The dashed lines represent the total yields that would be expected from the sum of the SM processes with the total WZ yields modified according to their correspondence to the given values of the associated anomalous coupling parameters. The SM prediction for the WZ process is obtained from the aTGC simulated sample with the anomalous couplings set to $0$. |
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Figure 15-b:
Distributions of discriminant observables in the anomalous couplings searches. The invariant mass of the three lepton plus the missing transverse momentum system (left) and the transverse mass of the same configuration (right). The dashed lines represent the total yields that would be expected from the sum of the SM processes with the total WZ yields modified according to their correspondence to the given values of the associated anomalous coupling parameters. The SM prediction for the WZ process is obtained from the aTGC simulated sample with the anomalous couplings set to $0$. |
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Figure 16:
2D confidence regions for each of the possible combinations of the considered aTGC parameters. The contours of the expected confidence regions for $68%$ and $95%$ confidence level are presented in each case. The parameters considered in each plot are $c_{\text {w}}-c_{\text {www}}$ (top), $c_{\text {w}}-c_{\text {b}}$ (middle) and $c_{\text {www}}-c_{\text {b}}$ (bottom). |
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Figure 16-a:
2D confidence regions for each of the possible combinations of the considered aTGC parameters. The contours of the expected confidence regions for $68%$ and $95%$ confidence level are presented in each case. The parameters considered in each plot are $c_{\text {w}}-c_{\text {www}}$ (top), $c_{\text {w}}-c_{\text {b}}$ (middle) and $c_{\text {www}}-c_{\text {b}}$ (bottom). |
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Figure 16-b:
2D confidence regions for each of the possible combinations of the considered aTGC parameters. The contours of the expected confidence regions for $68%$ and $95%$ confidence level are presented in each case. The parameters considered in each plot are $c_{\text {w}}-c_{\text {www}}$ (top), $c_{\text {w}}-c_{\text {b}}$ (middle) and $c_{\text {www}}-c_{\text {b}}$ (bottom). |
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Figure 16-c:
2D confidence regions for each of the possible combinations of the considered aTGC parameters. The contours of the expected confidence regions for $68%$ and $95%$ confidence level are presented in each case. The parameters considered in each plot are $c_{\text {w}}-c_{\text {www}}$ (top), $c_{\text {w}}-c_{\text {b}}$ (middle) and $c_{\text {www}}-c_{\text {b}}$ (bottom). |
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Figure 17:
Evolution of the expected confidence intervals in the EFT anomalous coupling parameters in terms of the cutoff scale given by different restrictions in the $M_{{\mathrm {W}} {\mathrm {Z}}}$ variable. For each point and parameter, the confidence intervals are computed imposing the additional restriction of no anomalous coupling contribution on top of SM prediction over the given value of $M_{{\mathrm {W}} {\mathrm {Z}}}$. Due to the statistical limitations in our simulation the last point is equivalent to no cut-off requirement being imposed. The parameter considered in each plot is: $c_{\textrm {w}}$ (top left), $c_{\textrm {www}}$ (top right) and $c_{\textrm {b}}$ (bottom). |
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Figure 17-a:
Evolution of the expected confidence intervals in the EFT anomalous coupling parameters in terms of the cutoff scale given by different restrictions in the $M_{{\mathrm {W}} {\mathrm {Z}}}$ variable. For each point and parameter, the confidence intervals are computed imposing the additional restriction of no anomalous coupling contribution on top of SM prediction over the given value of $M_{{\mathrm {W}} {\mathrm {Z}}}$. Due to the statistical limitations in our simulation the last point is equivalent to no cut-off requirement being imposed. The parameter considered in each plot is: $c_{\textrm {w}}$ (top left), $c_{\textrm {www}}$ (top right) and $c_{\textrm {b}}$ (bottom). |
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Figure 17-b:
Evolution of the expected confidence intervals in the EFT anomalous coupling parameters in terms of the cutoff scale given by different restrictions in the $M_{{\mathrm {W}} {\mathrm {Z}}}$ variable. For each point and parameter, the confidence intervals are computed imposing the additional restriction of no anomalous coupling contribution on top of SM prediction over the given value of $M_{{\mathrm {W}} {\mathrm {Z}}}$. Due to the statistical limitations in our simulation the last point is equivalent to no cut-off requirement being imposed. The parameter considered in each plot is: $c_{\textrm {w}}$ (top left), $c_{\textrm {www}}$ (top right) and $c_{\textrm {b}}$ (bottom). |
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Figure 17-c:
Evolution of the expected confidence intervals in the EFT anomalous coupling parameters in terms of the cutoff scale given by different restrictions in the $M_{{\mathrm {W}} {\mathrm {Z}}}$ variable. For each point and parameter, the confidence intervals are computed imposing the additional restriction of no anomalous coupling contribution on top of SM prediction over the given value of $M_{{\mathrm {W}} {\mathrm {Z}}}$. Due to the statistical limitations in our simulation the last point is equivalent to no cut-off requirement being imposed. The parameter considered in each plot is: $c_{\textrm {w}}$ (top left), $c_{\textrm {www}}$ (top right) and $c_{\textrm {b}}$ (bottom). |
| Tables | |
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Table 1:
Definition of the complete requirements for the definition of the signal (measurement) region of the analysis and the three different regions designed to control the behaviour of the main background sources. |
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Table 2:
Measured fiducial cross sections and their corresponding uncertainties for each of the individual flavour categories as well as for the combination of the four. |
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Table 3:
Expected and observed yields for each of the relevant processes and flavour categories. Combined statistical and systematic uncertainties are shown for each case except for the observed data yields for which only statistical uncertainties are shown. All expected yields correspond to quantities estimated after the maximum likelihood fit. Uncertainties are computed taking into account the full correlation matrix between sources of uncertainty, processes, and flavour categories. |
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Table 4:
Summary of the total postfit impact of each uncertainty source on the uncertainty of the signal strength measurement for each of the flavour categories and their combination. Theoretical uncertainties are only included in the signal acceptance during the extrapolation to the total phase space so they are not included in the likelihood fit. The values are percentages and correspond to the half-width between the up and down variation of each systematic uncertainty component. |
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Table 5:
Measured WZ production cross sections computed separately in each of the flavour categories. |
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Table 6:
Differential cross section in bins of leading jet ${p_{\mathrm {T}}}$. Values are expressed as fraction of the inclusive cross section. |
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Table 7:
Differential cross section in bins of Z boson ${p_{\mathrm {T}}}$. Values are expressed as fraction of the inclusive cross section. |
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Table 8:
Differential cross section in bins of mass of the WZ system. Values are expressed as fraction of the inclusive cross section. |
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Table 9:
Expected and observed 1-D confidence intervals at 95% confidence level for each of the considered AC parameters. |
| Summary |
|
The production process ${\mathrm{p}}{\mathrm{p}} \to \mathrm{W}\mathrm{Z}$ is studied in the trilepton final state at $\sqrt{s}= $ 13 TeV, using the full 2016 data set with a total integrated luminosity of 35.9 fb$^{-1}$. Fiducial results are obtained in each of the flavour categories and in the combined category, and are extrapolated for 60 $ < M_{\mathrm{W}\mathrm{Z}} < $ 120 GeV to the total WZ production cross section. Differential cross sections are measured as a function of the transverse momentum of the Z boson, of the transverse momentum of the leading jet, and of an estimate of the mass of the WZ system; results are compared with predictions from the POWHEG and MadGraph5\_aMC@NLO generators. Differential cross section are also measured depending on the sign of the W boson as a function of its transverse momentum. Confidence intervals for anomalous triple gauge-boson couplings are extracted for each of the anomalous couplings parameters for all the 1-D and 2-D possible combinations of parameters, using the $M_{\mathrm{W}\mathrm{Z}}$ variable in a maximum likelihood fit. The confidence intervals obtained represent the most stringent results on anomalous triple gauge-boson couplings to date. |
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Compact Muon Solenoid LHC, CERN |
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