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CMS-TOP-21-003 ; CERN-EP-2022-172
Search for new physics using effective field theory in 13 TeV pp collision events that contain a top quark pair and a boosted Z or Higgs boson
Phys. Rev. D 108 (2023) 032008
Abstract: A data sample containing top quark pairs (tˉt) produced in association with a Lorentz-boosted Z or Higgs boson is used to search for signs of new physics using effective field theory. The data correspond to an integrated luminosity of 138 fb1 of proton-proton collisions produced at a center-of-mass energy of 13 TeV at the LHC and collected by the CMS experiment. Selected events contain a single lepton and hadronic jets, including two identified with the decay of bottom quarks, plus an additional large-radius jet with high transverse momentum identified as a Z or Higgs boson decaying to a bottom quark pair. Machine learning techniques are employed to discriminate between tˉtZ or tˉtH events and events from background processes, which are dominated by tˉt+jets production. No indications of new physics are observed. The signal strengths of boosted tˉtZ and tˉtH production are measured, and upper limits are placed on the tˉtZ and tˉtH differential cross sections as functions of the Z or Higgs boson transverse momentum. The effects of new physics are probed using a framework in which the standard model is considered to be the low-energy effective field theory of a higher energy scale theory. Eight possible dimension-six operators are added to the standard model Lagrangian and their corresponding coefficients are constrained via fits to the data.
Figures & Tables Summary References CMS Publications
Figures

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Figure 1:
Examples of tree-level Feynman diagrams for the tˉtZ (left) and tˉtH (right) production processes.

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Figure 1-a:
Examples of tree-level Feynman diagrams for the tˉtZ (left) and tˉtH (right) production processes.

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Figure 1-b:
Examples of tree-level Feynman diagrams for the tˉtZ (left) and tˉtH (right) production processes.

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Figure 2:
The tˉtZ (left) and tˉtH (right) cross sections in the SM EFT, as ratios to the corresponding SM cross sections, as functions of ctZ/Λ2 and the Z boson pT (left), and cφtb/Λ2 and the Higgs boson pT (right), where ctZ and cφtb are the WCs for the EFT operators O(ij)uB and O(ij)φud, respectively [7]. Example Feynman diagrams, in which the vertices affected by ctZ and cφtb are marked by a filled dot, are also displayed.

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Figure 2-a:
The tˉtZ (left) and tˉtH (right) cross sections in the SM EFT, as ratios to the corresponding SM cross sections, as functions of ctZ/Λ2 and the Z boson pT (left), and cφtb/Λ2 and the Higgs boson pT (right), where ctZ and cφtb are the WCs for the EFT operators O(ij)uB and O(ij)φud, respectively [7]. Example Feynman diagrams, in which the vertices affected by ctZ and cφtb are marked by a filled dot, are also displayed.

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Figure 2-b:
The tˉtZ (left) and tˉtH (right) cross sections in the SM EFT, as ratios to the corresponding SM cross sections, as functions of ctZ/Λ2 and the Z boson pT (left), and cφtb/Λ2 and the Higgs boson pT (right), where ctZ and cφtb are the WCs for the EFT operators O(ij)uB and O(ij)φud, respectively [7]. Example Feynman diagrams, in which the vertices affected by ctZ and cφtb are marked by a filled dot, are also displayed.

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Figure 3:
The simulated DNN score distributions, normalized to unit area, for well-reconstructed tˉtZ and tˉtH signal events in which the reconstructed Z or Higgs boson candidate is matched to both generator-level b quark daughters of the Z or Higgs boson; the remaining tˉtZ and tˉtH events; background events from tˉt + bˉb; and background events from tˉt +cˉc and tˉt + LF. The events satisfy the baseline selection requirements described in Section 5 and contain a Z or Higgs boson candidate with pT> 300 GeV.

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Figure 4:
Soft-drop mass distributions from simulation for background (solid histograms) and signal (dashed histograms) of Z/Hbˉb candidate jets in three pT ranges: 200-300 GeV (upper left), 300-450 GeV (upper right), and >450GeV (lower) in simulated samples with DNN score >0.8. The signal distributions represent the SM prediction scaled up by a factor of 10 for easier comparison with the backgrounds. The signal distributions include well-reconstructed tˉtZ and tˉtH events as well as tˉtZ and tˉtH events that either do not contain Z/H bˉb or are not well reconstructed. The red hatched bands correspond to the statistical uncertainty in the background.

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Figure 4-a:
Soft-drop mass distributions from simulation for background (solid histograms) and signal (dashed histograms) of Z/Hbˉb candidate jets in three pT ranges: 200-300 GeV (upper left), 300-450 GeV (upper right), and >450GeV (lower) in simulated samples with DNN score >0.8. The signal distributions represent the SM prediction scaled up by a factor of 10 for easier comparison with the backgrounds. The signal distributions include well-reconstructed tˉtZ and tˉtH events as well as tˉtZ and tˉtH events that either do not contain Z/H bˉb or are not well reconstructed. The red hatched bands correspond to the statistical uncertainty in the background.

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Figure 4-b:
Soft-drop mass distributions from simulation for background (solid histograms) and signal (dashed histograms) of Z/Hbˉb candidate jets in three pT ranges: 200-300 GeV (upper left), 300-450 GeV (upper right), and >450GeV (lower) in simulated samples with DNN score >0.8. The signal distributions represent the SM prediction scaled up by a factor of 10 for easier comparison with the backgrounds. The signal distributions include well-reconstructed tˉtZ and tˉtH events as well as tˉtZ and tˉtH events that either do not contain Z/H bˉb or are not well reconstructed. The red hatched bands correspond to the statistical uncertainty in the background.

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Figure 4-c:
Soft-drop mass distributions from simulation for background (solid histograms) and signal (dashed histograms) of Z/Hbˉb candidate jets in three pT ranges: 200-300 GeV (upper left), 300-450 GeV (upper right), and >450GeV (lower) in simulated samples with DNN score >0.8. The signal distributions represent the SM prediction scaled up by a factor of 10 for easier comparison with the backgrounds. The signal distributions include well-reconstructed tˉtZ and tˉtH events as well as tˉtZ and tˉtH events that either do not contain Z/H bˉb or are not well reconstructed. The red hatched bands correspond to the statistical uncertainty in the background.

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Figure 5:
The percentage of simulated tˉtZ (left) and tˉtH (right) signal events that satisfy the baseline event selection requirements as well as the DNN and mass requirements in bins defined by the reconstructed AK8 jet pT (x axis) and simulated pTZ/H (y axis). The rightmost and uppermost bins are unbounded. The value of each bin is the ratio of the event yield in the bin to the total number of simulated signal events with a simulated pTZ/H in the same y-axis bin, including all decay modes of the top quark, Z boson, and Higgs boson. The color scale to the right shows the meaning of the histogram colors.

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Figure 5-a:
The percentage of simulated tˉtZ (left) and tˉtH (right) signal events that satisfy the baseline event selection requirements as well as the DNN and mass requirements in bins defined by the reconstructed AK8 jet pT (x axis) and simulated pTZ/H (y axis). The rightmost and uppermost bins are unbounded. The value of each bin is the ratio of the event yield in the bin to the total number of simulated signal events with a simulated pTZ/H in the same y-axis bin, including all decay modes of the top quark, Z boson, and Higgs boson. The color scale to the right shows the meaning of the histogram colors.

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Figure 5-b:
The percentage of simulated tˉtZ (left) and tˉtH (right) signal events that satisfy the baseline event selection requirements as well as the DNN and mass requirements in bins defined by the reconstructed AK8 jet pT (x axis) and simulated pTZ/H (y axis). The rightmost and uppermost bins are unbounded. The value of each bin is the ratio of the event yield in the bin to the total number of simulated signal events with a simulated pTZ/H in the same y-axis bin, including all decay modes of the top quark, Z boson, and Higgs boson. The color scale to the right shows the meaning of the histogram colors.

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Figure 6:
Postfit expected (solid histograms) and observed (points) yields for the 2016 (upper), 2017 (middle), and 2018 (lower) data-taking periods in each analysis bin. In the fit, the tˉtZ and tˉtH signal cross sections are fixed to the SM predictions. The analysis bins are defined as functions of the DNN score, and the pT and mSD of the boson candidate AK8 jet. The largest three groupings of bins in each year are defined by the AK8 jet pT. The next six groups are defined by the DNN score, and the smallest groups of three or four bins with the same pT and DNN score correspond to the AK8 jet mSD. The vertical bars on the points show the statistical uncertainty in the data. The lower panels in each plot give the ratio of the data to the sum of the MC predictions, with the red band representing the total uncertainty in the MC prediction.

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Figure 6-a:
Postfit expected (solid histograms) and observed (points) yields for the 2016 (upper), 2017 (middle), and 2018 (lower) data-taking periods in each analysis bin. In the fit, the tˉtZ and tˉtH signal cross sections are fixed to the SM predictions. The analysis bins are defined as functions of the DNN score, and the pT and mSD of the boson candidate AK8 jet. The largest three groupings of bins in each year are defined by the AK8 jet pT. The next six groups are defined by the DNN score, and the smallest groups of three or four bins with the same pT and DNN score correspond to the AK8 jet mSD. The vertical bars on the points show the statistical uncertainty in the data. The lower panels in each plot give the ratio of the data to the sum of the MC predictions, with the red band representing the total uncertainty in the MC prediction.

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Figure 6-b:
Postfit expected (solid histograms) and observed (points) yields for the 2016 (upper), 2017 (middle), and 2018 (lower) data-taking periods in each analysis bin. In the fit, the tˉtZ and tˉtH signal cross sections are fixed to the SM predictions. The analysis bins are defined as functions of the DNN score, and the pT and mSD of the boson candidate AK8 jet. The largest three groupings of bins in each year are defined by the AK8 jet pT. The next six groups are defined by the DNN score, and the smallest groups of three or four bins with the same pT and DNN score correspond to the AK8 jet mSD. The vertical bars on the points show the statistical uncertainty in the data. The lower panels in each plot give the ratio of the data to the sum of the MC predictions, with the red band representing the total uncertainty in the MC prediction.

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Figure 6-c:
Postfit expected (solid histograms) and observed (points) yields for the 2016 (upper), 2017 (middle), and 2018 (lower) data-taking periods in each analysis bin. In the fit, the tˉtZ and tˉtH signal cross sections are fixed to the SM predictions. The analysis bins are defined as functions of the DNN score, and the pT and mSD of the boson candidate AK8 jet. The largest three groupings of bins in each year are defined by the AK8 jet pT. The next six groups are defined by the DNN score, and the smallest groups of three or four bins with the same pT and DNN score correspond to the AK8 jet mSD. The vertical bars on the points show the statistical uncertainty in the data. The lower panels in each plot give the ratio of the data to the sum of the MC predictions, with the red band representing the total uncertainty in the MC prediction.

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Figure 7:
The observed best fit values (diamond) and SM predictions (star) for the signal strength modifiers μtˉtH versus μtˉtZ for generator-level pTH or pTZ> 200 GeV. The solid blue and dashed red contours show the 68 and 95% CL regions, respectively.

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Figure 8:
Observed and expected 95% CL upper limits on the tˉtZ (left) and tˉtH (right) differential cross sections as a function of the simulated Z and Higgs boson pT. The green and yellow bands indicate the regions containing 68 and 95%, respectively, of the distribution of limits under the SM hypothesis. The black lines represent the observed 95% CL upper limits. The magenta band shows the SM predicted differential cross sections with the PDF + αS and scale uncertainties. The lower panel shows the ratio of the observed and expected upper limits on the differential cross sections to the SM differential cross sections. The last bin is unbounded.

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Figure 8-a:
Observed and expected 95% CL upper limits on the tˉtZ (left) and tˉtH (right) differential cross sections as a function of the simulated Z and Higgs boson pT. The green and yellow bands indicate the regions containing 68 and 95%, respectively, of the distribution of limits under the SM hypothesis. The black lines represent the observed 95% CL upper limits. The magenta band shows the SM predicted differential cross sections with the PDF + αS and scale uncertainties. The lower panel shows the ratio of the observed and expected upper limits on the differential cross sections to the SM differential cross sections. The last bin is unbounded.

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Figure 8-b:
Observed and expected 95% CL upper limits on the tˉtZ (left) and tˉtH (right) differential cross sections as a function of the simulated Z and Higgs boson pT. The green and yellow bands indicate the regions containing 68 and 95%, respectively, of the distribution of limits under the SM hypothesis. The black lines represent the observed 95% CL upper limits. The magenta band shows the SM predicted differential cross sections with the PDF + αS and scale uncertainties. The lower panel shows the ratio of the observed and expected upper limits on the differential cross sections to the SM differential cross sections. The last bin is unbounded.

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Figure 9:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-a:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-b:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-c:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-d:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-e:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-f:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-g:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 9-h:
Observed (solid black) and expected (dotted red) scans of the negative log-likelihood as a function of each of the eight WCs when the seven other WCs are fixed to their SM values. The 68 and 95% CL intervals are indicated by thin gray lines.

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Figure 10:
The observed 68 and 95% CL intervals for the WCs are shown by the thick and thin bars, respectively. The intervals are found by scanning over a single WC while either profiling the other seven WCs (black) or fixing them to the SM value of zero (red).

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Figure 11:
Observed two-dimensional scans of the negative log-likelihood as a function of two of the eight WCs when all other WCs are fixed to their SM values. The three pairs of WCs scanned have the three largest observed correlation coefficients among all pairs. They are cφt versus cφQ (upper left), c3φQ versus cφQ (upper right), and ctW versus ctZ (lower). The 68, 95, and 99.7% CL intervals are indicated by the solid blue, dashed red, and dotted orange lines, respectively.

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Figure 11-a:
Observed two-dimensional scans of the negative log-likelihood as a function of two of the eight WCs when all other WCs are fixed to their SM values. The three pairs of WCs scanned have the three largest observed correlation coefficients among all pairs. They are cφt versus cφQ (upper left), c3φQ versus cφQ (upper right), and ctW versus ctZ (lower). The 68, 95, and 99.7% CL intervals are indicated by the solid blue, dashed red, and dotted orange lines, respectively.

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Figure 11-b:
Observed two-dimensional scans of the negative log-likelihood as a function of two of the eight WCs when all other WCs are fixed to their SM values. The three pairs of WCs scanned have the three largest observed correlation coefficients among all pairs. They are cφt versus cφQ (upper left), c3φQ versus cφQ (upper right), and ctW versus ctZ (lower). The 68, 95, and 99.7% CL intervals are indicated by the solid blue, dashed red, and dotted orange lines, respectively.

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Figure 11-c:
Observed two-dimensional scans of the negative log-likelihood as a function of two of the eight WCs when all other WCs are fixed to their SM values. The three pairs of WCs scanned have the three largest observed correlation coefficients among all pairs. They are cφt versus cφQ (upper left), c3φQ versus cφQ (upper right), and ctW versus ctZ (lower). The 68, 95, and 99.7% CL intervals are indicated by the solid blue, dashed red, and dotted orange lines, respectively.

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Figure 12:
Observed 95% CL intervals for the WCs. The intervals are found by scanning over a single WC while fixing the other seven to zero. For comparison, we also show the corresponding 95% CL intervals from Refs. [16,25,27,28], which used events with multiple leptons or photons. The intervals for several of the WCs would be too small to see clearly, and so we have increased their size by the factor given in the label on the left edge of the figure.

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Figure A1:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.

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Figure A1-a:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.

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Figure A1-b:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.

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Figure A1-c:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.

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Figure A1-d:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.

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Figure A1-e:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.

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Figure A1-f:
Prefit expected (colored histograms) and observed (point) distributions of selected DNN input variables, each of which is described in detail in Table A.1. These distributions represent the combined 2016-2018 data-taking periods. The hatched bands represent the total statistical and systematic uncertainty in the expected distributions, while the vertical bars on the black points indicate the statistical uncertainty in the observed distributions and the horizontal bars indicate the bin widths. The lower panels show the ratio of the observed yields to the sum of the MC predictions.
Tables

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Table 1:
The set of EFT operators considered in this analysis that affect the tˉtZ and tˉtH processes at order 1/Λ2. The couplings are restricted to involve only third-generation quarks. The symbol γμ denotes the Dirac matrices and σμνi(γμγνgμν), where gμν is the metric tensor and τI are the Pauli matrices. The field φ is the Higgs boson doublet and ˜φjεjk(φk), where εjk is the Levi-Civita symbol and ε12=+1. The quark doublet and the right-handed quark singlets are represented by q, u, and d, respectively. The quantities (φiDμφ)φ(iDμφ)(iDμφ)φ and (φiDIμφ)φτI(iDμφ)(iDμφ)τIφ, where Dμ is the covariant derivative. The symbols WIμν and Bμν are the field strength tensors for the weak isospin and weak hypercharge gauge fields. The abbreviations SW and CW denote the sine and cosine of the weak mixing angle in the unitary gauge, respectively. The operators marked with the symbol also require their Hermitian conjugate in the Lagrangian.

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Table 2:
Summary of the reconstructed object and event selection requirements.

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Table 3:
The observed and expected best fit (±1 standard deviation) signal strength modifiers μtˉtZ and μtˉtH for simulated pTZ or pTH> 200 GeV. The observed uncertainties are broken down into the components arising from the limited size of the data, the limited size of the simulation samples, experimental uncertainties, and theoretical uncertainties.

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Table 4:
The magnitudes of the major sources of systematic uncertainty in the measurement of the signal strength modifiers μtˉtZ and μtˉtH for simulated pTZ or pTH> 200 GeV.

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Table 5:
Observed and median expected 95% CL upper limits on the tˉtZ and tˉtH differential cross sections and on their ratios to the SM predictions for three pTZ/H intervals. The range given with the median expected 95% CL upper limits indicates the range in which 68% of the upper limits are expected to fall, assuming the SM hypothesis.

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Table 6:
Observed 95% CL intervals for the eight WCs in the EFT model. The intervals are determined by scanning over a single WC while either profiling the other seven WCs or fixing them to their SM value of zero.

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Table A1:
Comprehensive list of the input variables of the DNN, which is described in Section 6. The "+'' represents the relativistic four-momentum sum. Some variables are calculated for both the highest pT (leading) and second-highest pT (subleading) jet as indicated.
Summary
Measurements of the signal strengths and 95% confidence level upper limits on the differential cross sections for production of tˉtZ and tˉtH events, where H refers to the Higgs boson, are presented along with constraints on the Wilson coefficients of a leading-order effective field theory. The analysis is performed using the bˉb decay mode of the Z or Higgs boson and the lepton plus jets channel of the associated tˉt pair. The Z or Higgs boson is required to be Lorentz boosted, with transverse momentum pT> 200 GeV. A deep neural network is employed to discriminate between the tˉtZ and tˉtH signal events and the background, which is dominated by tˉt+jets production. The data correspond to an integrated luminosity of 138 fb1 collected with the CMS detector at the CERN LHC from 2016 through 2018. The data are binned as a function of the deep neural network score and the reconstructed pT and mass of the Z or Higgs boson. Binned maximum likelihood fits are employed to extract the observables from the data.

The data are found to be consistent with the expectations from the standard model. The signal strength modifiers for boosted tˉtZ and tˉtH production are measured to be μtˉtZ= 0.65+1.040.98 and μtˉtH= -0.27+0.860.83, which are both consistent with the expected value, 1. The 95% confidence level upper limits on the differential tˉtZ and tˉtH cross sections range from 2 to 5 times the standard model predicted cross sections for Z or Higgs boson pT> 300 GeV. Results are also presented on eight parameters of a leading-order effective field theory that have a large impact on boosted tˉtZ and tˉtH production. These results represent the most restrictive limits to date on the cross sections for the production of tˉtZ and tˉtH with Z or Higgs boson pT> 450 GeV. The limits on the Wilson coefficients in the effective field theory are consistent and, in some cases, competitive with the best previous limits.
References
1 V. C. Rubin and W. K. Ford, Jr. Rotation of the Andromeda nebula from a spectroscopic survey of emission regions Astrophys. J. 159 (1970) 379
2 Planck Collaboration Planck 2018 results. VI. cosmological parameters Astron. Astrophys. 641 (2020) A6 1807.06209
3 D. Clowe, A. Gonzalez, and M. Markevitch Weak lensing mass reconstruction of the interacting cluster 1E 0657-558: Direct evidence for the existence of dark matter Astrophys. J. 604 (2004) 596 astro-ph/0312273
4 R. K. Kaul and P. Majumdar Cancellation of quadratically divergent mass corrections in globally supersymmetric spontaneously broken gauge theories NPB 199 (1982) 36
5 R. Barbieri and G. F. Giudice Upper bounds on supersymmetric particle masses NPB 306 (1988) 63
6 W. Buchmuller and D. Wyler Effective Lagrangian analysis of new interactions and flavor conservation NPB 268 (1986) 621
7 B. Grzadkowski, M. Iskrzyński, M. Misiak, and J. Rosiek Dimension-six terms in the standard model Lagrangian JHEP 10 (2010) 085 1008.4884
8 A. Falkowski and R. Rattazzi Which EFT JHEP 10 (2019) 255 1902.05936
9 C. Degrande et al. Effective field theory: A modern approach to anomalous couplings Annals Phys. 335 (2013) 21 1205.4231
10 A. Kobach Baryon number, lepton number, and operator dimension in the standard model PLB 758 (2016) 455 1604.05726
11 Particle Data Group, P. A. Zyla et al. Review of particle physics Prog. Theor. Exp. Phys. 2020 (2020) 083C01
12 J. A. Aguilar-Saavedra et al. Interpreting top-quark LHC measurements in the standard-model effective field theory LHC TOP WG note CERN-LPCC-2018-01 1802.07237
13 ATLAS Collaboration Measurement of the tˉtZ and tˉtW cross sections in proton-proton collisions at s= 13 TeV with the ATLAS detector PRD 99 (2019) 072009 1901.03584
14 ATLAS Collaboration Measurements of the inclusive and differential production cross sections of a top-quark-antiquark pair in association with a Z boson at s= 13 TeV with the ATLAS detector EPJC 81 (2021) 737 2103.12603
15 CMS Collaboration Measurement of the cross section for top quark pair production in association with a W or Z boson in proton-proton collisions at s= 13 TeV JHEP 08 (2018) 011 CMS-TOP-17-005
1711.02547
16 CMS Collaboration Measurement of top quark pair production in association with a Z boson in proton-proton collisions at s= 13 TeV JHEP 03 (2020) 056 CMS-TOP-18-009
1907.11270
17 ATLAS Collaboration Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector PLB 784 (2018) 173 1806.00425
18 ATLAS Collaboration CP properties of Higgs boson interactions with top quarks in the tˉtH and tH processes using H γγ with the ATLAS detector PRL 125 (2020) 061802 2004.04545
19 ATLAS Collaboration Measurement of Higgs boson decay into b-quarks in associated production with a top-quark pair in pp collisions at s= 13 TeV with the ATLAS detector JHEP 06 (2022) 097 2111.06712
20 CMS Collaboration Observation of tˉtH production PRL 120 (2018) 231801 CMS-HIG-17-035
1804.02610
21 CMS Collaboration Search for tˉtH production in the all-jet final state in proton-proton collisions at s= 13 TeV JHEP 06 (2018) 101 CMS-HIG-17-022
1803.06986
22 CMS Collaboration Search for tˉtH production in the H bˉb decay channel with leptonic tˉt decays in proton-proton collisions at s= 13 TeV JHEP 03 (2019) 026 CMS-HIG-17-026
1804.03682
23 CMS Collaboration Measurements of tˉtH production and the CP structure of the Yukawa interaction between the Higgs boson and top quark in the diphoton decay channel PRL 125 (2020) 061801 CMS-HIG-19-013
2003.10866
24 CMS Collaboration Measurement of the Higgs boson production rate in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at s= 13 TeV EPJC 81 (2021) 378 CMS-HIG-19-008
2011.03652
25 CMS Collaboration Search for new physics in top quark production with additional leptons in proton-proton collisions at s= 13 TeV using effective field theory JHEP 03 (2021) 095 CMS-TOP-19-001
2012.04120
26 CMS Collaboration Measurement of the inclusive and differential tˉtγ cross sections in the single-lepton channel and EFT interpretation at s= 13 TeV JHEP 12 (2021) 180 CMS-TOP-18-010
2107.01508
27 CMS Collaboration Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at s= 13 TeV JHEP 12 (2021) 083 CMS-TOP-21-001
2107.13896
28 CMS Collaboration Measurement of the inclusive and differential tˉtγ cross sections in the dilepton channel and effective field theory interpretation in proton-proton collisions at s= 13 TeV JHEP 05 (2022) 091 CMS-TOP-21-004
2201.07301
29 CMS Collaboration HEPData record for this analysis link
30 CMS Collaboration Performance of the CMS Level-1 trigger in proton-proton collisions at s= 13 TeV JINST 15 (2020) P10017 CMS-TRG-17-001
2006.10165
31 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
32 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004 CMS-00-001
33 CMS Collaboration Precision luminosity measurement in proton-proton collisions at s= 13 TeV in 2015 and 2016 at CMS EPJC 81 (2021) 800 CMS-LUM-17-003
2104.01927
34 CMS Collaboration CMS luminosity measurement for the 2017 data-taking period at s= 13 TeV CMS-PAS-LUM-17-004 CMS-PAS-LUM-17-004
35 CMS Collaboration CMS luminosity measurement for the 2018 data-taking period at s= 13 TeV CMS-PAS-LUM-18-002 CMS-PAS-LUM-18-002
36 J. Alwall et al. The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations JHEP 07 (2014) 079 1405.0301
37 P. Nason A new method for combining NLO QCD with shower Monte Carlo algorithms JHEP 11 (2004) 040 hep-ph/0409146
38 S. Frixione, P. Nason, and C. Oleari Matching NLO QCD computations with parton shower simulations: the POWHEG method JHEP 11 (2007) 070 0709.2092
39 S. Alioli, P. Nason, C. Oleari, and E. Re A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX JHEP 06 (2010) 043 1002.2581
40 H. B. Hartanto, B. Jager, L. Reina, and D. Wackeroth Higgs boson production in association with top quarks in the POWHEG BOX PRD 91 (2015) 094003 1501.04498
41 A. Kulesza et al. Associated production of a top quark pair with a heavy electroweak gauge boson at NLO+NNLL accuracy EPJC 79 (2019) 249 1812.08622
42 LHC Higgs Cross Section Working Group Handbook of LHC Higgs cross sections: 4. Deciphering the nature of the Higgs sector CERN-2017-002-M 1610.07922
43 G. Ridolfi, M. Ubiali, and M. Zaro A fragmentation-based study of heavy quark production JHEP 01 (2020) 196 1911.01975
44 T. Ježo, J. M. Lindert, N. Moretti, and S. Pozzorini New NLOPS predictions for tˉt+b-jet production at the LHC EPJC 78 (2018) 502 1802.00426
45 F. Buccioni, S. Kallweit, S. Pozzorini, and M. F. Zoller NLO QCD predictions for tˉtbˉb production in association with a light jet at the LHC JHEP 12 (2019) 015 1907.13624
46 S. Frixione, P. Nason, and G. Ridolfi A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction JHEP 09 (2007) 126 0707.3088
47 M. Czakon et al. Top-pair production at the LHC through NNLO QCD and NLO EW JHEP 10 (2017) 186 1705.04105
48 M. Beneke, P. Falgari, S. Klein, and C. Schwinn Hadronic top-quark pair production with NNLL threshold resummation NPB 855 (2012) 695 1109.1536
49 M. Cacciari et al. Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation PLB 710 (2012) 612 1111.5869
50 P. Barnreuther, M. Czakon, and A. Mitov Percent-level-precision physics at the Tevatron: next-to-next-to-leading order QCD corrections to qˉqtˉt + X PRL 109 (2012) 132001 1204.5201
51 M. Czakon and A. Mitov NNLO corrections to top-pair production at hadron colliders: the all-fermionic scattering channels JHEP 12 (2012) 054 1207.0236
52 M. Czakon and A. Mitov NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction JHEP 01 (2013) 080 1210.6832
53 M. Czakon, P. Fiedler, and A. Mitov Total top-quark pair-production cross section at hadron colliders through O(αS4) PRL 110 (2013) 252004 1303.6254
54 M. Czakon and A. Mitov Top++: a program for the calculation of the top-pair cross-section at hadron colliders CPC 185 (2014) 2930 1112.5675
55 S. Alioli, P. Nason, C. Oleari, and E. Re NLO single-top production matched with shower in POWHEG: s- and t-channel contributions JHEP 09 (2009) 111 0907.4076
56 E. Re Single-top Wt-channel production matched with parton showers using the POWHEG method EPJC 71 (2011) 1547 1009.2450
57 S. Quackenbush, R. Gavin, Y. Li, and F. Petriello W physics at the LHC with FEWZ 2.1 CPC 184 (2013) 209 1201.5896
58 Y. Li and F. Petriello Combining QCD and electroweak corrections to dilepton production in the framework of the FEWZ simulation code PRD 86 (2012) 094034 1208.5967
59 N. Kidonakis Two-loop soft anomalous dimensions for single top quark associated production with a W or H PRD 82 (2010) 054018 1005.4451
60 M. Aliev et al. HATHOR: hadronic top and heavy quarks cross section calculator CPC 182 (2011) 1034 1007.1327
61 P. Kant et al. HatHor for single top-quark production: updated predictions and uncertainty estimates for single top-quark production in hadronic collisions CPC 191 (2015) 74 1406.4403
62 R. Frederix and S. Frixione Merging meets matching in MC@NLO JHEP 12 (2012) 061 1209.6215
63 M. L. Mangano, M. Moretti, F. Piccinini, and M. Treccani Matching matrix elements and shower evolution for top-pair production in hadronic collisions JHEP 01 (2007) 013 hep-ph/0611129
64 CMS Collaboration Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements EPJC 80 (2020) 4 CMS-GEN-17-001
1903.12179
65 CMS Collaboration Event generator tunes obtained from underlying event and multiparton scattering measurements EPJC 76 (2016) 155 CMS-GEN-14-001
1512.00815
66 NNPDF Collaboration Parton distributions from high-precision collider data EPJC 77 (2017) 663 1706.00428
67 NNPDF Collaboration Parton distributions for the LHC run II JHEP 04 (2015) 040 1410.8849
68 GEANT4 Collaboration GEANT4--a simulation toolkit NIMA 506 (2003) 250
69 R. Goldouzian et al. Matching in pp tˉtW/Z/h + jet SMEFT studies JHEP 06 (2021) 151 2012.06872
70 C. Degrande et al. Automated one-loop computations in the standard model effective field theory PRD 103 (2021) 096024 2008.11743
71 CMS Collaboration Particle-flow reconstruction and global event description with the CMS detector JINST 12 (2017) P10003 CMS-PRF-14-001
1706.04965
72 CMS Collaboration Performance of missing transverse momentum reconstruction in proton-proton collisions at s= 13 TeV using the CMS detector JINST 14 (2019) P07004 CMS-JME-17-001
1903.06078
73 CMS Collaboration Technical proposal for the Phase-II upgrade of the Compact Muon Solenoid CMS-PAS-TDR-15-002 CMS-PAS-TDR-15-002
74 CMS Collaboration Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at s= 8 TeV JINST 10 (2015) P06005 CMS-EGM-13-001
1502.02701
75 CMS Collaboration Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at s= 13 TeV JINST 13 (2018) P06015 CMS-MUO-16-001
1804.04528
76 CMS Collaboration Search for supersymmetry in pp collisions at s= 13 TeV in the single-lepton final state using the sum of masses of large-radius jets JHEP 08 (2016) 122 CMS-SUS-15-007
1605.04608
77 M. Cacciari, G. P. Salam, and G. Soyez The anti-kT jet clustering algorithm JHEP 04 (2008) 063 0802.1189
78 M. Cacciari, G. P. Salam, and G. Soyez FastJet user manual EPJC 72 (2012) 1896 1111.6097
79 CMS Collaboration Pileup mitigation at CMS in 13 TeV data JINST 15 (2020) P09018 CMS-JME-18-001
2003.00503
80 D. Bertolini, P. Harris, M. Low, and N. Tran Pileup per particle identification JHEP 10 (2014) 059 1407.6013
81 M. Dasgupta, A. Fregoso, S. Marzani, and G. P. Salam Towards an understanding of jet substructure JHEP 09 (2013) 029 1307.0007
82 A. J. Larkoski, S. Marzani, G. Soyez, and J. Thaler Soft drop JHEP 05 (2014) 146 1402.2657
83 CMS Collaboration Identification of heavy, energetic, hadronically decaying particles using machine-learning techniques JINST 15 (2020) P06005 CMS-JME-18-002
2004.08262
84 M. Cacciari and G. P. Salam Pileup subtraction using jet areas PLB 659 (2008) 119 0707.1378
85 CMS Collaboration Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV JINST 12 (2017) P02014 CMS-JME-13-004
1607.03663
86 CMS Collaboration Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV JINST 13 (2018) P05011 CMS-BTV-16-002
1712.07158
87 J. G. Kreer A question of terminology IRE Trans. Inf. Theory 3 (1957) 208
88 C. E. Shannon A mathematical theory of communication Bell Syst. Tech. J. 27 (1948) 379
89 ATLAS Collaboration Measurement of event shapes at large momentum transfer with the ATLAS detector in pp collisions at s= 7 TeV EPJC 72 (2012) 2211 1206.2135
90 S. Ioffe and C. Szegedy Batch normalization: accelerating deep network training by reducing internal covariate shift Proc. Mach. Learn. Res. 37 (2015) 448 1502.03167
91 N. Srivastava et al. Dropout: a simple way to prevent neural networks from overfitting J. Mach. Learn. Res. 15 (2014) 1929
92 T.-Y. Lin et al. Focal loss for dense object detection IEEE Trans. Pattern Anal. Mach. Intell. 42 (2020) 318 1708.02002
93 R. J. Barlow and C. Beeston Fitting using finite Monte Carlo samples CPC 77 (1993) 219
94 J. S. Conway Incorporating nuisance parameters in likelihoods for multisource spectra in PHYSTAT 2011 2011 1103.0354
95 J. Butterworth et al. PDF4LHC recommendations for LHC run II JPG 43 (2016) 023001 1510.03865
96 CMS Collaboration First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at s= 13 TeV PLB 820 (2021) 136565 CMS-TOP-20-003
2012.09225
97 CMS Collaboration Measurement of the inelastic proton-proton cross section at s= 13 TeV JHEP 07 (2018) 161 CMS-FSQ-15-005
1802.02613
98 CMS Collaboration Jet algorithms performance in 13 TeV data CMS Physics Analysis Summary, 2017
CMS-PAS-JME-16-003
CMS-PAS-JME-16-003
99 ATLAS and CMS Collaborations, and LHC Higgs Combination Group Procedure for the LHC Higgs boson search combination in Summer 2011 CMS-NOTE-2011-005
100 G. Cowan, K. Cranmer, E. Gross, and O. Vitells Asymptotic formulae for likelihood-based tests of new physics EPJC 71 (2011) 1554 1007.1727
101 T. Junk Confidence level computation for combining searches with small statistics NIMA 434 (1999) 435 hep-ex/9902006
102 A. L. Read Presentation of search results: The CLs technique JPG 28 (2002) 2693
103 CMS Collaboration Measurement and interpretation of differential cross sections for Higgs boson production at s= 13 TeV PLB 792 (2019) 369 CMS-HIG-17-028
1812.06504
104 CMS Collaboration Measurement of the cross section for tˉt production with additional jets and b jets in pp collisions at s= 13 TeV JHEP 07 (2020) 125 CMS-TOP-18-002
2003.06467
105 CMS Collaboration Measurement of the tˉtbˉb production cross section in the all-jet final state in pp collisions at s= 13 TeV PLB 803 (2020) 135285 CMS-TOP-18-011
1909.05306
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