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| CMS-HIG-22-011 ; CERN-EP-2024-026 | ||
| Search for ZZ and ZH production in the $ \mathrm{b} \bar{\mathrm{b}}\mathrm{b} \bar{\mathrm{b}} $ final state using proton-proton collisions at $ \sqrt{s}= $ 13 TeV | ||
| CMS Collaboration | ||
| 29 March 2024 | ||
| EPJC 84 (2024) 712 | ||
| Abstract: A search for ZZ and ZH production in the $ \mathrm{b} \bar{\mathrm{b}}\mathrm{b} \bar{\mathrm{b}} $ final state is presented, where H is the standard model (SM) Higgs boson. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosity of 133 fb$ ^{-1} $ collected at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. The analysis introduces several novel techniques for deriving and validating a multi-dimensional background model based on control samples in data. A multiclass multivariate classifier customized for the $ \mathrm{b} \bar{\mathrm{b}}\mathrm{b} \bar{\mathrm{b}} $ final state is developed to derive the background model and extract the signal. The data are found to be consistent, within uncertainties, with the SM predictions. The observed (expected) upper limits at 95% confidence level are found to be 3.8 (3.8) and 5.0 (2.9) times the SM prediction for the ZZ and ZH production cross sections, respectively. | ||
| Links: e-print arXiv:2403.20241 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; | ||
| Figures & Tables | Summary | Additional Figures | References | CMS Publications |
|---|
| Figures | |
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Figure 1:
Signal yield from simulation (left) and from four-tag events in data (right), as a function of $ m_{\mathrm{jj}}^{\text{lead}} $ and $ m_{\mathrm{jj}}^{\text{subl}} $. The color scale to the right of each plot gives the range of values. The signal region is defined by the union of the regions enclosed by the dashed red contours. |
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Figure 1-a:
Signal yield from simulation (left) and from four-tag events in data (right), as a function of $ m_{\mathrm{jj}}^{\text{lead}} $ and $ m_{\mathrm{jj}}^{\text{subl}} $. The color scale to the right of each plot gives the range of values. The signal region is defined by the union of the regions enclosed by the dashed red contours. |
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Figure 1-b:
Signal yield from simulation (left) and from four-tag events in data (right), as a function of $ m_{\mathrm{jj}}^{\text{lead}} $ and $ m_{\mathrm{jj}}^{\text{subl}} $. The color scale to the right of each plot gives the range of values. The signal region is defined by the union of the regions enclosed by the dashed red contours. |
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Figure 2:
Event selection acceptance times efficiency as a function of the generated four-body mass $ m_{4\mathrm{b}}^{\text{gen}} $ for the ZZ (left) and ZH (right) signals. The plots show the cumulative efficiency with respect to the inclusive sample. The expected $ m_{4\mathrm{b}}^{\text{gen}} $ distributions of the inclusive ZZ and ZH events are shown by the gray-shaded areas with arbitrary normalization. |
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Figure 2-a:
Event selection acceptance times efficiency as a function of the generated four-body mass $ m_{4\mathrm{b}}^{\text{gen}} $ for the ZZ (left) and ZH (right) signals. The plots show the cumulative efficiency with respect to the inclusive sample. The expected $ m_{4\mathrm{b}}^{\text{gen}} $ distributions of the inclusive ZZ and ZH events are shown by the gray-shaded areas with arbitrary normalization. |
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Figure 2-b:
Event selection acceptance times efficiency as a function of the generated four-body mass $ m_{4\mathrm{b}}^{\text{gen}} $ for the ZZ (left) and ZH (right) signals. The plots show the cumulative efficiency with respect to the inclusive sample. The expected $ m_{4\mathrm{b}}^{\text{gen}} $ distributions of the inclusive ZZ and ZH events are shown by the gray-shaded areas with arbitrary normalization. |
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Figure 3:
A high-level sketch of the HCR classifier architecture. Boson-candidate jets are shown on the left with the three possible jet pairings. The HCR architecture is shown on the right. The boxes represent pixels, with the labels indicating which jet, dijet, or quadjet the pixel refers to. The different jet pairings on the left are each represented within the network, as indicated by the color coding. The output P(class) corresponds to the the probability that an event belongs to the corresponding class used in training. |
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Figure 4:
Jet (left) and b-tagged jet (right) multiplicity distributions in the SB region. The black data points show the observed four-tag data, the blue distribution the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, and the yellow histogram the three-tag multijet prior to the JCM corrections. The red histogram shows the result of the fit to the JCM model. The quality of the fit is given by the $ \chi^2 $ per degrees of freedom (dof) and corresponding $ p $-value in the legend. The lower panels display the ratio of the data to the fit prediction. |
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Figure 4-a:
Jet (left) and b-tagged jet (right) multiplicity distributions in the SB region. The black data points show the observed four-tag data, the blue distribution the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, and the yellow histogram the three-tag multijet prior to the JCM corrections. The red histogram shows the result of the fit to the JCM model. The quality of the fit is given by the $ \chi^2 $ per degrees of freedom (dof) and corresponding $ p $-value in the legend. The lower panels display the ratio of the data to the fit prediction. |
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Figure 4-b:
Jet (left) and b-tagged jet (right) multiplicity distributions in the SB region. The black data points show the observed four-tag data, the blue distribution the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, and the yellow histogram the three-tag multijet prior to the JCM corrections. The red histogram shows the result of the fit to the JCM model. The quality of the fit is given by the $ \chi^2 $ per degrees of freedom (dof) and corresponding $ p $-value in the legend. The lower panels display the ratio of the data to the fit prediction. |
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Figure 5:
Distributions of $ \Delta \text{R}(j, j)_{\text{close}} $ (left) and $ \Delta \text{R}(j, j)_{\text{complement}} $ (right). The four-tag SB events are shown by the points. The QCD multijet distribution (yellow region) is from the three-tag SB sample after the JCM correction but before the FvT kinematic reweighting, and the $ \mathrm{t} \bar{\mathrm{t}} $ distribution (blue region) is from simulation. The lower panels display the ratio of the four-tag data to the total background, which is the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the background. |
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Figure 5-a:
Distributions of $ \Delta \text{R}(j, j)_{\text{close}} $ (left) and $ \Delta \text{R}(j, j)_{\text{complement}} $ (right). The four-tag SB events are shown by the points. The QCD multijet distribution (yellow region) is from the three-tag SB sample after the JCM correction but before the FvT kinematic reweighting, and the $ \mathrm{t} \bar{\mathrm{t}} $ distribution (blue region) is from simulation. The lower panels display the ratio of the four-tag data to the total background, which is the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the background. |
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Figure 5-b:
Distributions of $ \Delta \text{R}(j, j)_{\text{close}} $ (left) and $ \Delta \text{R}(j, j)_{\text{complement}} $ (right). The four-tag SB events are shown by the points. The QCD multijet distribution (yellow region) is from the three-tag SB sample after the JCM correction but before the FvT kinematic reweighting, and the $ \mathrm{t} \bar{\mathrm{t}} $ distribution (blue region) is from simulation. The lower panels display the ratio of the four-tag data to the total background, which is the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the background. |
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Figure 6:
Distributions of the signal probabilities for ZZ (left) and ZH (right) in the SB region, respectively. The four-tag SB events are shown by the points. The QCD multijet distribution (yellow region) is from the three-tag SB sample after the JCM correction but before the FvT kinematic reweighting, and the $ \mathrm{t} \bar{\mathrm{t}} $ distribution (blue region) is from simulation. The lower panels display the ratio of the four-tag data to the total background, which is the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the background. |
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Figure 6-a:
Distributions of the signal probabilities for ZZ (left) and ZH (right) in the SB region, respectively. The four-tag SB events are shown by the points. The QCD multijet distribution (yellow region) is from the three-tag SB sample after the JCM correction but before the FvT kinematic reweighting, and the $ \mathrm{t} \bar{\mathrm{t}} $ distribution (blue region) is from simulation. The lower panels display the ratio of the four-tag data to the total background, which is the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the background. |
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Figure 6-b:
Distributions of the signal probabilities for ZZ (left) and ZH (right) in the SB region, respectively. The four-tag SB events are shown by the points. The QCD multijet distribution (yellow region) is from the three-tag SB sample after the JCM correction but before the FvT kinematic reweighting, and the $ \mathrm{t} \bar{\mathrm{t}} $ distribution (blue region) is from simulation. The lower panels display the ratio of the four-tag data to the total background, which is the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the background. |
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Figure 7:
The $ \Delta\text{R}(j,j) $ distributions shown in Figure 5 after including the FvT corrections to the QCD multijet prediction. |
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Figure 7-a:
The $ \Delta\text{R}(j,j) $ distributions shown in Figure 5 after including the FvT corrections to the QCD multijet prediction. |
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Figure 7-b:
The $ \Delta\text{R}(j,j) $ distributions shown in Figure 5 after including the FvT corrections to the QCD multijet prediction. |
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Figure 8:
Distribution of signal probabilities for ZZ (left) and ZH (right) events in the SB region after including the FvT corrections to the QCD multijet prediction. |
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Figure 8-a:
Distribution of signal probabilities for ZZ (left) and ZH (right) events in the SB region after including the FvT corrections to the QCD multijet prediction. |
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Figure 8-b:
Distribution of signal probabilities for ZZ (left) and ZH (right) events in the SB region after including the FvT corrections to the QCD multijet prediction. |
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Figure 9:
An illustration of the hemisphere mixing procedure, adapted from Ref. [20]. Three-tag events are divided into two halves by cutting along the axis perpendicular to the transverse thrust axis. In a preliminary step, each event in the four-tag data set is split into two hemispheres that are collected in a library of hemispheres. Once the library is created, each three-tag event is used as a basis for creating a synthetic event. These are constructed by picking the two hemispheres from the library that are most similar to the hemispheres making up the original event. |
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Figure 10:
Distribution of signal probabilities for ZZ (upper row) and ZH (lower row) events in the sideband (left) and signal regions (right). The four-tag events are shown by the points. The QCD multijet distribution before the FvT corrections is given by the yellow region, and the simulated $ \mathrm{t} \bar{\mathrm{t}} $ distribution by the blue area. The average of the mixed models (red) provides a high-event-count proxy of the 4b background (black) that allows the extrapolation of the background model to be tested precisely. The lower panels display the ratio of the four-tag data to the average of the mixed models (red) and to the QCD multijet distribution (black). |
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Figure 10-a:
Distribution of signal probabilities for ZZ (upper row) and ZH (lower row) events in the sideband (left) and signal regions (right). The four-tag events are shown by the points. The QCD multijet distribution before the FvT corrections is given by the yellow region, and the simulated $ \mathrm{t} \bar{\mathrm{t}} $ distribution by the blue area. The average of the mixed models (red) provides a high-event-count proxy of the 4b background (black) that allows the extrapolation of the background model to be tested precisely. The lower panels display the ratio of the four-tag data to the average of the mixed models (red) and to the QCD multijet distribution (black). |
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Figure 10-b:
Distribution of signal probabilities for ZZ (upper row) and ZH (lower row) events in the sideband (left) and signal regions (right). The four-tag events are shown by the points. The QCD multijet distribution before the FvT corrections is given by the yellow region, and the simulated $ \mathrm{t} \bar{\mathrm{t}} $ distribution by the blue area. The average of the mixed models (red) provides a high-event-count proxy of the 4b background (black) that allows the extrapolation of the background model to be tested precisely. The lower panels display the ratio of the four-tag data to the average of the mixed models (red) and to the QCD multijet distribution (black). |
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Figure 10-c:
Distribution of signal probabilities for ZZ (upper row) and ZH (lower row) events in the sideband (left) and signal regions (right). The four-tag events are shown by the points. The QCD multijet distribution before the FvT corrections is given by the yellow region, and the simulated $ \mathrm{t} \bar{\mathrm{t}} $ distribution by the blue area. The average of the mixed models (red) provides a high-event-count proxy of the 4b background (black) that allows the extrapolation of the background model to be tested precisely. The lower panels display the ratio of the four-tag data to the average of the mixed models (red) and to the QCD multijet distribution (black). |
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Figure 10-d:
Distribution of signal probabilities for ZZ (upper row) and ZH (lower row) events in the sideband (left) and signal regions (right). The four-tag events are shown by the points. The QCD multijet distribution before the FvT corrections is given by the yellow region, and the simulated $ \mathrm{t} \bar{\mathrm{t}} $ distribution by the blue area. The average of the mixed models (red) provides a high-event-count proxy of the 4b background (black) that allows the extrapolation of the background model to be tested precisely. The lower panels display the ratio of the four-tag data to the average of the mixed models (red) and to the QCD multijet distribution (black). |
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Figure 11:
The distributions of the ZZ (left) and ZH (right) signal probabilities. The black data points show the average of the mixed models. The yellow and blue distributions show the average of the QCD multijet models and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The red histogram displays the post-fit results of the data fit to the background model. The ZZ channel data distribution is fit with all five basic coefficients constrained, while the ZH channel distribution has two of the four coefficients unconstrained. The lower panels give the pre- (blue) and post-fit (red) pulls. |
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Figure 11-a:
The distributions of the ZZ (left) and ZH (right) signal probabilities. The black data points show the average of the mixed models. The yellow and blue distributions show the average of the QCD multijet models and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The red histogram displays the post-fit results of the data fit to the background model. The ZZ channel data distribution is fit with all five basic coefficients constrained, while the ZH channel distribution has two of the four coefficients unconstrained. The lower panels give the pre- (blue) and post-fit (red) pulls. |
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Figure 11-b:
The distributions of the ZZ (left) and ZH (right) signal probabilities. The black data points show the average of the mixed models. The yellow and blue distributions show the average of the QCD multijet models and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The red histogram displays the post-fit results of the data fit to the background model. The ZZ channel data distribution is fit with all five basic coefficients constrained, while the ZH channel distribution has two of the four coefficients unconstrained. The lower panels give the pre- (blue) and post-fit (red) pulls. |
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Figure 12:
Distributions of signal probabilities for ZZ (left) and ZH (right) channels (points), along with the post-fit QCD multijet (yellow region) plus $ \mathrm{t} \bar{\mathrm{t}} $ (blue region) distributions. The ZH and ZZ signal distributions scaled to the fitted signal strengths are shown, stacked on top of the background prediction. The expected ZH (red histograms) and ZZ (green histograms) signal channel distributions are also shown separately, multiplied by 100 for visibility. The lower panels display the ratio of the data to the result of the signal plus background fit, with the hatched area showing the uncertainty in the combined fit. |
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Figure 12-a:
Distributions of signal probabilities for ZZ (left) and ZH (right) channels (points), along with the post-fit QCD multijet (yellow region) plus $ \mathrm{t} \bar{\mathrm{t}} $ (blue region) distributions. The ZH and ZZ signal distributions scaled to the fitted signal strengths are shown, stacked on top of the background prediction. The expected ZH (red histograms) and ZZ (green histograms) signal channel distributions are also shown separately, multiplied by 100 for visibility. The lower panels display the ratio of the data to the result of the signal plus background fit, with the hatched area showing the uncertainty in the combined fit. |
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Figure 12-b:
Distributions of signal probabilities for ZZ (left) and ZH (right) channels (points), along with the post-fit QCD multijet (yellow region) plus $ \mathrm{t} \bar{\mathrm{t}} $ (blue region) distributions. The ZH and ZZ signal distributions scaled to the fitted signal strengths are shown, stacked on top of the background prediction. The expected ZH (red histograms) and ZZ (green histograms) signal channel distributions are also shown separately, multiplied by 100 for visibility. The lower panels display the ratio of the data to the result of the signal plus background fit, with the hatched area showing the uncertainty in the combined fit. |
| Tables | |
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Table 1:
Summary of the relative uncertainties form the various sources in the measured signal strength, expressed as a percentage of the total uncertainty for the ZZ and ZH channels. The two uncertainties coming from the background modeling are given separately in parentheses, as well as their sum. The total systematic uncertainties shown include the effects of correlations. |
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Table 2:
Expected and observed ZZ and ZH signal strengths and their corresponding 95% CL upper limits. The expected signal strengths and the corresponding expected upper limits shown in parentheses include only the statistical uncertainties. The upper limits are obtained from a fit to the SvB signal probabilities under the hypothesis of no $ \mathrm{Z}\mathrm{Z}\to 4\mathrm{b} $ or $ \mathrm{Z}\mathrm{H}\to 4\mathrm{b} $ signal. |
| Summary |
| A search for ZZ and ZH production in the 4b final state is presented. The search uses the full 2016--2018 data set of proton-proton collisions at a center-of-mass energy of 13 TeV recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 133 fb$ ^{-1} $. The analysis benefits from a multiclass multivariate classifier, which uses convolutions to solve the combinatoric jet pairing problem, and has been designed with an architecture customized to the 4b final state. The classifier is used both for signal-versus-background discrimination and for the derivation and validation of the background model. A novel technique for assessing the background modeling uncertainties, using a synthetic data sample, produced using a hemisphere mixing procedure, allows both the uncertainty in the background model and its variance to be measured with a precision better than the statistical uncertainties in the selected signal-region events. While these techniques are developed and demonstrated in the ZZ and $ \mathrm{Z}\mathrm{H} \to $ 4b searches, they are directly applicable to the $ \mathrm{H}\mathrm{H} \to 4\mathrm{b} $ analysis. The observed (expected) 95% CL upper limits on the $ \mathrm{Z}\mathrm{Z} \to 4\mathrm{b} $ and $ \mathrm{Z}\mathrm{H} \to 4\mathrm{b} $ production cross sections correspond to 3.8 (3.8) and 5.0 (2.9) times the standard model prediction, respectively. |
| Additional Figures | |
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Additional Figure 1:
Acceptance times efficiency as a function of the generated four-body $ m_{4\mathrm{b}}^{\textrm{gen}} $ for the five different event selection requirements for simulated ZZ (left) and ZH (right). |
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Additional Figure 1-a:
Acceptance times efficiency as a function of the generated four-body $ m_{4\mathrm{b}}^{\textrm{gen}} $ for the five different event selection requirements for simulated ZZ (left) and ZH (right). |
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Additional Figure 1-b:
Acceptance times efficiency as a function of the generated four-body $ m_{4\mathrm{b}}^{\textrm{gen}} $ for the five different event selection requirements for simulated ZZ (left) and ZH (right). |
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Additional Figure 2:
The ZZ (left) and ZH (right) signal efficiences from simulation versus the background efficiency for the nominal HCR SvB classier including additional jets, and for a simpler two-dimensional likelihood classifier using the two dijet invariant masses. A version of the HCR SvB classifier that does not include additional jets is also shown. |
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Additional Figure 2-a:
The ZZ (left) and ZH (right) signal efficiences from simulation versus the background efficiency for the nominal HCR SvB classier including additional jets, and for a simpler two-dimensional likelihood classifier using the two dijet invariant masses. A version of the HCR SvB classifier that does not include additional jets is also shown. |
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Additional Figure 2-b:
The ZZ (left) and ZH (right) signal efficiences from simulation versus the background efficiency for the nominal HCR SvB classier including additional jets, and for a simpler two-dimensional likelihood classifier using the two dijet invariant masses. A version of the HCR SvB classifier that does not include additional jets is also shown. |
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Additional Figure 3:
Distributions of the FvT classifier weights before (left) and after (right) applying the FvT corrections for the four-tag data (points), and the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ backgrounds (yellow and blue distributions, respectively). The lower panels display the ratio of the data to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched region represents the uncertainties in the background. |
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Additional Figure 3-a:
Distributions of the FvT classifier weights before (left) and after (right) applying the FvT corrections for the four-tag data (points), and the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ backgrounds (yellow and blue distributions, respectively). The lower panels display the ratio of the data to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched region represents the uncertainties in the background. |
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Additional Figure 3-b:
Distributions of the FvT classifier weights before (left) and after (right) applying the FvT corrections for the four-tag data (points), and the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ backgrounds (yellow and blue distributions, respectively). The lower panels display the ratio of the data to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched region represents the uncertainties in the background. |
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Additional Figure 4:
The SvB signal probability distributions in the ZZ SR for one of the mixed data samples (left) and the average of the fifteen mixed samples (right). The points show the mixed model results, the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ background distributions are shown by the yellow and blue regions, respectively. The expected signal distributions for ZZ and ZH are shown by the green and red histograms, multiplied by 100. The lower panels display the ratio of the mixed sample distribution to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the ratio. |
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Additional Figure 4-a:
The SvB signal probability distributions in the ZZ SR for one of the mixed data samples (left) and the average of the fifteen mixed samples (right). The points show the mixed model results, the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ background distributions are shown by the yellow and blue regions, respectively. The expected signal distributions for ZZ and ZH are shown by the green and red histograms, multiplied by 100. The lower panels display the ratio of the mixed sample distribution to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the ratio. |
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Additional Figure 4-b:
The SvB signal probability distributions in the ZZ SR for one of the mixed data samples (left) and the average of the fifteen mixed samples (right). The points show the mixed model results, the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ background distributions are shown by the yellow and blue regions, respectively. The expected signal distributions for ZZ and ZH are shown by the green and red histograms, multiplied by 100. The lower panels display the ratio of the mixed sample distribution to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the ratio. |
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Additional Figure 5:
The SvB signal probability distributions in the ZH SR for one of the mixed data samples (left) and the average of the fifteen mixed samples (right). The points show the mixed model results, the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ background distributions are shown by the yellow and blue regions, respectively. The expected signal distributions for ZZ and ZH are shown by the green and red histograms, multiplied by 100. The lower panels display the ratio of the mixed sample distribution to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the ratio. |
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Additional Figure 5-a:
The SvB signal probability distributions in the ZH SR for one of the mixed data samples (left) and the average of the fifteen mixed samples (right). The points show the mixed model results, the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ background distributions are shown by the yellow and blue regions, respectively. The expected signal distributions for ZZ and ZH are shown by the green and red histograms, multiplied by 100. The lower panels display the ratio of the mixed sample distribution to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the ratio. |
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Additional Figure 5-b:
The SvB signal probability distributions in the ZH SR for one of the mixed data samples (left) and the average of the fifteen mixed samples (right). The points show the mixed model results, the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ background distributions are shown by the yellow and blue regions, respectively. The expected signal distributions for ZZ and ZH are shown by the green and red histograms, multiplied by 100. The lower panels display the ratio of the mixed sample distribution to the sum of the QCD multijet and $ \mathrm{t} \bar{\mathrm{t}} $ distributions. The hatched area gives the statistical uncertainty in the ratio. |
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Additional Figure 6:
The predicted QCD multijet ZZ SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
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Additional Figure 6-a:
The predicted QCD multijet ZZ SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
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Additional Figure 6-b:
The predicted QCD multijet ZZ SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
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Additional Figure 6-c:
The predicted QCD multijet ZZ SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
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Additional Figure 6-d:
The predicted QCD multijet ZZ SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 6-e:
The predicted QCD multijet ZZ SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 7:
The predicted QCD multijet ZH SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 7-a:
The predicted QCD multijet ZH SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 7-b:
The predicted QCD multijet ZH SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 7-c:
The predicted QCD multijet ZH SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 7-d:
The predicted QCD multijet ZH SvB probability distributions for each of the 15 mixed data sample SRs (yellow regions). The distribution from each mixed data sample is offset by the data sample index number. The black points give the average of the 15 data samples. The solid blue curves show a fit to the individual distributions using an increasing number of basis functions from one in the upper left plot to five in the lowest plot. The lower panels show the pulls before (yellow histogram) and after (blue histogram) adding the basis corrections. The correlation coefficient (r) for a fit testing for correlations is given in the legend, along with the p-value used to test for lack of correlation. Basis functions are added until the p-value is greater than 5%. |
png pdf |
Additional Figure 8:
Distributions of the ZH signal probability for the average observed SR yields from the mixed models. The yellow and blue regions give the distributions of the average of the QCD multijet models and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The red histogram displays the post-fit results of the data fit to the background model with 0 (left) and 1 unconstrained parameter (right) in the fit. The $ \chi^2 $ / dof and the p-value from the fit are shown in the legend. The lower panels give the pre- (blue histograms) and post-fit (red histograms) pulls. |
png pdf |
Additional Figure 8-a:
Distributions of the ZH signal probability for the average observed SR yields from the mixed models. The yellow and blue regions give the distributions of the average of the QCD multijet models and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The red histogram displays the post-fit results of the data fit to the background model with 0 (left) and 1 unconstrained parameter (right) in the fit. The $ \chi^2 $ / dof and the p-value from the fit are shown in the legend. The lower panels give the pre- (blue histograms) and post-fit (red histograms) pulls. |
png pdf |
Additional Figure 8-b:
Distributions of the ZH signal probability for the average observed SR yields from the mixed models. The yellow and blue regions give the distributions of the average of the QCD multijet models and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The red histogram displays the post-fit results of the data fit to the background model with 0 (left) and 1 unconstrained parameter (right) in the fit. The $ \chi^2 $ / dof and the p-value from the fit are shown in the legend. The lower panels give the pre- (blue histograms) and post-fit (red histograms) pulls. |
png pdf |
Additional Figure 9:
The pre-fit signal SvB signal probability distributions for the ZZ (left) and ZH (right). The black points show the four-tag events from data. The yellow and blue regions show the predictions from the QCD multijet model and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The predictions for the ZH and ZZ signal distributions are given by the red and and blue histograms, respectively, multiplied by 100. The lower panels show the ratio of the data to the background, with the hatched area representing the uncertainty in the background. |
png pdf |
Additional Figure 9-a:
The pre-fit signal SvB signal probability distributions for the ZZ (left) and ZH (right). The black points show the four-tag events from data. The yellow and blue regions show the predictions from the QCD multijet model and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The predictions for the ZH and ZZ signal distributions are given by the red and and blue histograms, respectively, multiplied by 100. The lower panels show the ratio of the data to the background, with the hatched area representing the uncertainty in the background. |
png pdf |
Additional Figure 9-b:
The pre-fit signal SvB signal probability distributions for the ZZ (left) and ZH (right). The black points show the four-tag events from data. The yellow and blue regions show the predictions from the QCD multijet model and the $ \mathrm{t} \bar{\mathrm{t}} $ simulation, respectively. The predictions for the ZH and ZZ signal distributions are given by the red and and blue histograms, respectively, multiplied by 100. The lower panels show the ratio of the data to the background, with the hatched area representing the uncertainty in the background. |
png pdf |
Additional Figure 10:
Distributions of signal probabilities for ZZ (left) and ZH (right) channels (points), along with the post background-only fit QCD multijet (yellow region) plus $ \mathrm{t} \bar{\mathrm{t}} $ (blue region) distributions. The expected ZH (red lines) and ZZ (blue lines) signal channel distributions are shown, multiplied by 100 for visibility. The lower panels display the ratio of the data to the total background, with the hatched area showing the uncertainty in the background. |
png pdf |
Additional Figure 10-a:
Distributions of signal probabilities for ZZ (left) and ZH (right) channels (points), along with the post background-only fit QCD multijet (yellow region) plus $ \mathrm{t} \bar{\mathrm{t}} $ (blue region) distributions. The expected ZH (red lines) and ZZ (blue lines) signal channel distributions are shown, multiplied by 100 for visibility. The lower panels display the ratio of the data to the total background, with the hatched area showing the uncertainty in the background. |
png pdf |
Additional Figure 10-b:
Distributions of signal probabilities for ZZ (left) and ZH (right) channels (points), along with the post background-only fit QCD multijet (yellow region) plus $ \mathrm{t} \bar{\mathrm{t}} $ (blue region) distributions. The expected ZH (red lines) and ZZ (blue lines) signal channel distributions are shown, multiplied by 100 for visibility. The lower panels display the ratio of the data to the total background, with the hatched area showing the uncertainty in the background. |
png pdf |
Additional Figure 11:
Distributions of $\Delta \text{R}_{\mathrm{jj}}^{\text{lead}}$ (left) and $\Delta \text{R}_{\mathrm{jj}}^{\text{subl}}$ (right) as a function of the four-jet mass for signal (top) and four-tag data (bottom). Events falling between the red lines satisfy the selection defined in Eq. 2. |
png pdf |
Additional Figure 11-a:
Distributions of $\Delta \text{R}_{\mathrm{jj}}^{\text{lead}}$ (left) and $\Delta \text{R}_{\mathrm{jj}}^{\text{subl}}$ (right) as a function of the four-jet mass for signal (top) and four-tag data (bottom). Events falling between the red lines satisfy the selection defined in Eq. 2. |
png pdf |
Additional Figure 11-b:
Distributions of $\Delta \text{R}_{\mathrm{jj}}^{\text{lead}}$ (left) and $\Delta \text{R}_{\mathrm{jj}}^{\text{subl}}$ (right) as a function of the four-jet mass for signal (top) and four-tag data (bottom). Events falling between the red lines satisfy the selection defined in Eq. 2. |
png pdf |
Additional Figure 11-c:
Distributions of $\Delta \text{R}_{\mathrm{jj}}^{\text{lead}}$ (left) and $\Delta \text{R}_{\mathrm{jj}}^{\text{subl}}$ (right) as a function of the four-jet mass for signal (top) and four-tag data (bottom). Events falling between the red lines satisfy the selection defined in Eq. 2. |
png pdf |
Additional Figure 11-d:
Distributions of $\Delta \text{R}_{\mathrm{jj}}^{\text{lead}}$ (left) and $\Delta \text{R}_{\mathrm{jj}}^{\text{subl}}$ (right) as a function of the four-jet mass for signal (top) and four-tag data (bottom). Events falling between the red lines satisfy the selection defined in Eq. 2. |
png pdf |
Additional Figure 12:
Distribution of background probabilities, QCD-multijet (left) and $ \mathrm{t} \overline{\mathrm{t}} $ (right), for events in the SR region after including the FvT corrections to the QCD multijet prediction. |
png pdf |
Additional Figure 12-a:
Distribution of background probabilities, QCD-multijet (left) and $ \mathrm{t} \overline{\mathrm{t}} $ (right), for events in the SR region after including the FvT corrections to the QCD multijet prediction. |
png pdf |
Additional Figure 12-b:
Distribution of background probabilities, QCD-multijet (left) and $ \mathrm{t} \overline{\mathrm{t}} $ (right), for events in the SR region after including the FvT corrections to the QCD multijet prediction. |
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