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| CMS-PAS-SMP-24-012 | ||
| Measurement of the jet mass and W boson mass in hadronic decays of boosted W bosons at 13 TeV | ||
| CMS Collaboration | ||
| 2025-07-08 | ||
| Abstract: The jet mass of W bosons decaying to a quark-antiquark pair is measured in W+jets events from proton-proton collisions at a center-of-mass energy of $ \sqrt{s}= $ 13 TeV. The data used were collected by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 138 fb$ ^{-1} $. Hadronic decays of W bosons with high momenta produce strongly collimated decay products due to the large Lorentz boost, and are reconstructed as single large-radius jets. These jets have a characteristic substructure that is exploited to distinguish them from the large background of quark- and gluon-initiated jets. The jet mass is computed using the soft drop algorithm, which suppresses soft wide-angle radiation that leads to a broadening of the jet mass distribution. Unfolded measurements are presented of the double-differential cross section as a function of the jet transverse momentum and soft-drop mass. From these distributions, the first measurement of the W boson mass in an all-jets final state at a hadron collider is obtained, with a value of 80.77 $ \pm $ 0.57 GeV. | ||
| Links: CDS record (PDF) ; CADI line (restricted) ; | ||
| Figures | |
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Figure 1:
Feynman diagram for tree-level $ \mathrm{W}(\mathrm{q}\overline{\mathrm{q}}) $+jets production. |
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Figure 2:
Acceptance $ \mathcal{A} $ as a function of $ m_\mathrm{SD}^\mathrm{ptcl} $ without (left) and with (right) the requirement $ N_{2}^{(1)} < $ 0.2 at the particle level. The acceptance is calculated using the $ \mathrm{W}(\mathrm{q}\overline{\mathrm{q}}) $+jets signal simulation with 2018 detector conditions. |
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Figure 2-a:
Acceptance $ \mathcal{A} $ as a function of $ m_\mathrm{SD}^\mathrm{ptcl} $ without (left) and with (right) the requirement $ N_{2}^{(1)} < $ 0.2 at the particle level. The acceptance is calculated using the $ \mathrm{W}(\mathrm{q}\overline{\mathrm{q}}) $+jets signal simulation with 2018 detector conditions. |
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Figure 2-b:
Acceptance $ \mathcal{A} $ as a function of $ m_\mathrm{SD}^\mathrm{ptcl} $ without (left) and with (right) the requirement $ N_{2}^{(1)} < $ 0.2 at the particle level. The acceptance is calculated using the $ \mathrm{W}(\mathrm{q}\overline{\mathrm{q}}) $+jets signal simulation with 2018 detector conditions. |
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Figure 3:
Reconstructed $ m_\mathrm{SD}^\mathrm{reco} $ distributions in the second $ p_{\mathrm{T}}^\mathrm{reco} $ bin with 650 $ < p_{\mathrm{T}}^\mathrm{reco} \leq $ 725 GeV in the signal (upper row) and control (lower row) regions defined using the $ N_{2}^{(1),\mathrm{DDT}} $ (left) and $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ (right) taggers. All four data-taking periods (early 2016, late 2016, 2017, and 2018) are combined, resulting in a total integrated luminosity of 138 fb$ ^{-1} $. |
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Figure 3-a:
Reconstructed $ m_\mathrm{SD}^\mathrm{reco} $ distributions in the second $ p_{\mathrm{T}}^\mathrm{reco} $ bin with 650 $ < p_{\mathrm{T}}^\mathrm{reco} \leq $ 725 GeV in the signal (upper row) and control (lower row) regions defined using the $ N_{2}^{(1),\mathrm{DDT}} $ (left) and $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ (right) taggers. All four data-taking periods (early 2016, late 2016, 2017, and 2018) are combined, resulting in a total integrated luminosity of 138 fb$ ^{-1} $. |
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Figure 3-b:
Reconstructed $ m_\mathrm{SD}^\mathrm{reco} $ distributions in the second $ p_{\mathrm{T}}^\mathrm{reco} $ bin with 650 $ < p_{\mathrm{T}}^\mathrm{reco} \leq $ 725 GeV in the signal (upper row) and control (lower row) regions defined using the $ N_{2}^{(1),\mathrm{DDT}} $ (left) and $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ (right) taggers. All four data-taking periods (early 2016, late 2016, 2017, and 2018) are combined, resulting in a total integrated luminosity of 138 fb$ ^{-1} $. |
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Figure 3-c:
Reconstructed $ m_\mathrm{SD}^\mathrm{reco} $ distributions in the second $ p_{\mathrm{T}}^\mathrm{reco} $ bin with 650 $ < p_{\mathrm{T}}^\mathrm{reco} \leq $ 725 GeV in the signal (upper row) and control (lower row) regions defined using the $ N_{2}^{(1),\mathrm{DDT}} $ (left) and $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ (right) taggers. All four data-taking periods (early 2016, late 2016, 2017, and 2018) are combined, resulting in a total integrated luminosity of 138 fb$ ^{-1} $. |
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Figure 3-d:
Reconstructed $ m_\mathrm{SD}^\mathrm{reco} $ distributions in the second $ p_{\mathrm{T}}^\mathrm{reco} $ bin with 650 $ < p_{\mathrm{T}}^\mathrm{reco} \leq $ 725 GeV in the signal (upper row) and control (lower row) regions defined using the $ N_{2}^{(1),\mathrm{DDT}} $ (left) and $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ (right) taggers. All four data-taking periods (early 2016, late 2016, 2017, and 2018) are combined, resulting in a total integrated luminosity of 138 fb$ ^{-1} $. |
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Figure 4:
Residual function $ r(\hat{p}_{T}, \hat{\rho}_\mathrm{SD}) $ obtained from a fit to data, when using the $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ as jet tagger. |
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Figure 5:
Summary of the effect of the systematic uncertainties in the reconstructed soft drop jet mass in the $ \mathrm{W}(\mathrm{q}\overline{\mathrm{q}}) $+jets signal sample in a representative $ p_{\mathrm{T}}^\mathrm{reco} $ bin. The dominant shape effects can be attributed to uncertainties in the hadronization model, jet energy scale, and final-state shower. The jet energy scale and final state shower mainly affect the region of the W boson mass peak (70 $ < m_\mathrm{SD}^\mathrm{reco} < $ 110 GeV). These lead to a shift of events from the peak region on top of a falling background, thus affecting most strongly the number of events at the right-hand side of the W boson mass peak (90 $ < m_\mathrm{SD}^\mathrm{reco} < $ 110 GeV). The size of the hadronization model uncertainty is smallest at the W boson mass peak and mainly affects the tails of the W boson mass distribution ($ m_\mathrm{SD}^\mathrm{reco} < $ 70 GeV and $ m_\mathrm{SD}^\mathrm{reco} > $ 90 GeV) where light-flavor quark and gluon jets dominate [10]. The double peak structure at 120 GeV and 190 GeV is a consequence of the fact that MadGraph-5_aMC@NLO+PYTHIA and MadGraph-5_aMC@NLO+ HERWIG predict different slopes in this region. |
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Figure 6:
Response matrix obtained for selected events in simulation. The matrix is obtained from a sum of all data-taking eras, corresponding to an integrated luminosity of 138 fb$ ^{-1} $. The bin borders drawn with dashed lines correspond to the $ p_{\mathrm{T}} $-bins. Within each $ p_{\mathrm{T}} $-bin, the bins correspond to those of $ m_\mathrm{SD} $. |
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Figure 7:
Unfolded jet mass distribution at the particle level for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin obtained with $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $. The fiducial measurement region at the particle level includes the $ N_{2}^{(1)} < $ 0.2 selection. The unfolded data are shown as black markers, the blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. |
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Figure 7-a:
Unfolded jet mass distribution at the particle level for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin obtained with $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $. The fiducial measurement region at the particle level includes the $ N_{2}^{(1)} < $ 0.2 selection. The unfolded data are shown as black markers, the blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. |
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Figure 7-b:
Unfolded jet mass distribution at the particle level for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin obtained with $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $. The fiducial measurement region at the particle level includes the $ N_{2}^{(1)} < $ 0.2 selection. The unfolded data are shown as black markers, the blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. |
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Figure 7-c:
Unfolded jet mass distribution at the particle level for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin obtained with $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $. The fiducial measurement region at the particle level includes the $ N_{2}^{(1)} < $ 0.2 selection. The unfolded data are shown as black markers, the blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. |
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Figure 8:
Correlation matrix of the maximum likelihood estimators of the signal strength modifiers \POI with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition. The plot shows the matrix from the fit to the data using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $. The grey dashed lines indicate the individual $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. |
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Figure 9:
Unfolded jet mass distribution at the particle level for $ p_{\mathrm{T}}^\mathrm{ptcl} > $ 650 GeV, obtained by summing all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. The results are obtained using the PARTICLENET} ^\MATHRM{DDT tagger without (left) and with (right) the $ N_{2}^{(1)} < $ 0.2 selection at the particle level without matching to a W boson in the particle-level definition. The unfolded data are shown as black markers. The blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. Predictions with different values of the W boson mass generated with PYTHIA at LO and scaled to match the total number of events in data are overlaid. |
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Figure 9-a:
Unfolded jet mass distribution at the particle level for $ p_{\mathrm{T}}^\mathrm{ptcl} > $ 650 GeV, obtained by summing all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. The results are obtained using the PARTICLENET} ^\MATHRM{DDT tagger without (left) and with (right) the $ N_{2}^{(1)} < $ 0.2 selection at the particle level without matching to a W boson in the particle-level definition. The unfolded data are shown as black markers. The blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. Predictions with different values of the W boson mass generated with PYTHIA at LO and scaled to match the total number of events in data are overlaid. |
png pdf |
Figure 9-b:
Unfolded jet mass distribution at the particle level for $ p_{\mathrm{T}}^\mathrm{ptcl} > $ 650 GeV, obtained by summing all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. The results are obtained using the PARTICLENET} ^\MATHRM{DDT tagger without (left) and with (right) the $ N_{2}^{(1)} < $ 0.2 selection at the particle level without matching to a W boson in the particle-level definition. The unfolded data are shown as black markers. The blue lines show the predictions from MadGraph-5_aMC@NLO+PYTHIA at LO with MLM matching and supplemented by NLO QCD and EWK corrections. The theory uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections, and is drawn as a light shaded blue band. The purely perturbative uncertainties are overlaid as a dark, shaded blue band. Predictions with different values of the W boson mass generated with PYTHIA at LO and scaled to match the total number of events in data are overlaid. |
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Figure 10:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using ParticleNet$ ^\mathrm{DDT} $ tagger without (left) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. The matching to a W boson further removes contributions to the cross section where the jet originates from a quark or gluon recoiling against the W boson and, resulting in reduced shower and hadronization uncertainties. |
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Figure 10-a:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using ParticleNet$ ^\mathrm{DDT} $ tagger without (left) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. The matching to a W boson further removes contributions to the cross section where the jet originates from a quark or gluon recoiling against the W boson and, resulting in reduced shower and hadronization uncertainties. |
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Figure 10-b:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using ParticleNet$ ^\mathrm{DDT} $ tagger without (left) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. The matching to a W boson further removes contributions to the cross section where the jet originates from a quark or gluon recoiling against the W boson and, resulting in reduced shower and hadronization uncertainties. |
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Figure 11:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 11-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 11-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 11-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 12:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ in the background estimation. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 12-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ in the background estimation. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 12-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ in the background estimation. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 12-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ in the background estimation. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 13:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 13-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 13-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 13-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 14:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and without (let) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, without (upper row) and with (lower row) matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 14-a:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and without (let) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, without (upper row) and with (lower row) matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 14-b:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and without (let) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, without (upper row) and with (lower row) matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 14-c:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and without (let) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, without (upper row) and with (lower row) matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 14-d:
Jet mass distribution of the sum of all $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and without (let) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut at particle-level, without (upper row) and with (lower row) matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 15:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 15-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 15-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 15-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ with matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 16:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 16-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 16-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 16-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition and matching to a W boson in the particle-level definition. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 17:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 17-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 17-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 17-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 18:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 18-a:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 18-b:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
png pdf |
Figure 18-c:
Jet mass distribution for each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin resulting from the unfolding using $ N_{2}^{(1),\mathrm{DDT}} $ and with inclusion of a $ N_{2}^{(1)} < $ 0.2 cut. The unfolded data is shown as black markers, the blue line shows the true distribution from the simulation with theory uncertainties added as the shaded blue band. |
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Figure 19:
Correlation matrix of the maximum likelihood estimators of the signal strength modifiers \POI without $ N_{2}^{(1)} $ cut in the particle-level definition. The plot shows the matrix from the fit to data using $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $. The grey dashed lines indicate the individual $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. |
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Figure 20:
Correlation matrix of the maximum likelihood estimators of the signal strength modifiers \POI without (left) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition. The plot shows the matrix from the fit to data using $ N_{2}^{(1),\mathrm{DDT}} $. The grey dashed lines indicate the individual $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. |
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Figure 20-a:
Correlation matrix of the maximum likelihood estimators of the signal strength modifiers \POI without (left) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition. The plot shows the matrix from the fit to data using $ N_{2}^{(1),\mathrm{DDT}} $. The grey dashed lines indicate the individual $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. |
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Figure 20-b:
Correlation matrix of the maximum likelihood estimators of the signal strength modifiers \POI without (left) and with (right) inclusion of a $ N_{2}^{(1)} < $ 0.2 cut in the particle-level definition. The plot shows the matrix from the fit to data using $ N_{2}^{(1),\mathrm{DDT}} $. The grey dashed lines indicate the individual $ p_{\mathrm{T}}^\mathrm{ptcl} $ bins. |
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Figure 21:
Closure test of the W boson mass extraction procedure. The x-axis corresponds to the W boson mass parameter set in PYTHIA simulation used in place of the data. The y-axis corresponds to the measured value, where the data used in place of the data is excluded from the list of templates used for carrying out the measurement. |
| Tables | |
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Table 1:
Summary of signal ($ \varepsilon_{\mathrm{W}\!+\!\mathrm{jets}} $) and background ($ \varepsilon_{\mathrm{bkg}} $) efficiencies in the different signal (pass) and control (fail) regions for the $ N_{2}^{(1),\mathrm{DDT}} $ and $ P^{\mathrm{PN, DDT}}_{\mathrm{W vs. QCD}} $ taggers in the fully-hadronic $ \mathrm{W}(\mathrm{q}\overline{\mathrm{q}}) $+jets selection. The efficiencies are estimated from simulation and averaged over the years of data-taking. |
png pdf |
Table 2:
Fiducial cross sections predicted with MadGraph-5_aMC@NLO$ + $PYTHIA at NLO QCD with EWK corrrections after different stages of the particle-level selection. The given uncertainty is the sum in quadrature of parton shower variations and the hadronization model uncertainty, as well as the uncertainties in the QCD and EW corrections. |
png pdf |
Table 3:
Summary of systematic uncertainties and their impact on the measurement in each $ p_{\mathrm{T}}^\mathrm{ptcl} $ bin, using the PARTICLENET} ^\MATHRM{DDT tagger. The ranges indicate the minimal and maximal effects on the cross section across all $ m_\mathrm{SD}^\mathrm{ptcl} $ bins. |
png pdf |
Table 4:
Fiducial cross section predicted from MadGraph-5_aMC@NLO$ + $PYTHIA with NLO QCD and EWK corrrections after the particle-level selection. |
| Summary |
| The jet mass of W bosons decaying to a quark-antiquark pair is measured in W+jets events from proton-proton collisions at the LHC at a center-of-mass energy of $ \sqrt{s} = $ 13 TeV. The data were collected by the CMS experiment in 2016--2018 and correspond to an integrated luminosity of 138 fb$ ^{-1} $. The measurement considers W bosons with large momenta, resulting in strongly collimated decay products that are reconstructed in a single large-radius jet. Jets initiated by W bosons with a characteristic two-prong substructure are distinguished from single light-flavor quark and gluon-initiated background jets using a selection based on the substructure of these jets. The jet mass is measured using the soft drop algorithm, which suppresses soft and wide-angle radiation that can obscure the resonance peak of the W boson at its rest mass. We report the double-differential cross section in bins of the jet transverse momentum and soft drop mass. The unfolded data are found to be in agreement with predictions from simulations at leading order with MLM matching, supplemented by next-to-leading order quantum chromodynamics and electroweak corrections. The first measurement of the W boson mass in an all-jets final state at a hadron collider is reported, with a value of 80.77 $ \pm $ 0.57 GeV. |
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