CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

CMS-HIG-21-006 ; CERN-EP-2022-157
Search for CP violation in ttH and tH production in multilepton channels in proton-proton collisions at $ \sqrt{s} = $ 13 TeV
JHEP 07 (2023) 092
Abstract: The charge-parity (CP) structure of the Yukawa interaction between the Higgs (H) boson and the top quark is measured in a data sample enriched in the ttH and tH associated production, using 138 fb$^{-1}$ of data collected in proton-proton collisions at $\sqrt{s} = $ 13 TeV by the CMS experiment at the CERN LHC. The study targets events where the H boson decays via H $\to$ WW or H $\to\tau\tau$ and the top quarks decay via t $\to$ Wb: the W bosons decay either leptonically or hadronically, and final states characterized by the presence of at least two leptons are studied. Machine learning techniques are applied to these final states to enhance the separation of CP-even from CP-odd scenarios. Two-dimensional confidence regions are set on ${\kappa_{\mathrm{t}}}$ and ${\tilde{\kappa}_{\mathrm{t}}}$, which are respectively defined as the CP-even and CP-odd top-Higgs Yukawa coupling modifiers. No significant fractional CP-odd contributions, parameterized by the quantity ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|}$ are observed; the parameter is determined to be ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} =$ 0.59 with an interval of (0.24, 0.81) at 68% confidence level. The results are combined with previous results covering the H $\to$ ZZ and H $\to\gamma\gamma$ decay modes, yielding two- and one-dimensional confidence regions on ${\kappa_{\mathrm{t}}}$ and ${\tilde{\kappa}_{\mathrm{t}}}$, while ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|}$ is determined to be ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} =$ 0.28 with an interval of ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} <$ 0.55 at 68% confidence level, in agreement with the standard model CP-even prediction of ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} =$ 0.
Figures & Tables Summary Additional Figures References CMS Publications
Figures

png pdf
Figure 1:
Representative Feynman diagrams for the ttH production processes.

png pdf
Figure 1-a:
Representative Feynman diagrams for the ttH production processes.

png pdf
Figure 1-b:
Representative Feynman diagrams for the ttH production processes.

png pdf
Figure 2:
Upper (lower) row: representative Feynman diagrams for the tH process in the $ t $-channel ($tW-associated) production mode.

png pdf
Figure 2-a:
Upper (lower) row: representative Feynman diagrams for the tH process in the $ t $-channel ($tW-associated) production mode.

png pdf
Figure 2-b:
Upper (lower) row: representative Feynman diagrams for the tH process in the $ t $-channel ($tW-associated) production mode.

png pdf
Figure 2-c:
Upper (lower) row: representative Feynman diagrams for the tH process in the $ t $-channel ($tW-associated) production mode.

png pdf
Figure 2-d:
Upper (lower) row: representative Feynman diagrams for the tH process in the $ t $-channel ($tW-associated) production mode.

png pdf
Figure 3:
One of the most important input variables for the CP discriminant, $ M_{\mathrm{t}\overline{\mathrm{t}}\mathrm{H}} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 3-a:
One of the most important input variables for the CP discriminant, $ M_{\mathrm{t}\overline{\mathrm{t}}\mathrm{H}} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 3-b:
One of the most important input variables for the CP discriminant, $ M_{\mathrm{t}\overline{\mathrm{t}}\mathrm{H}} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 3-c:
One of the most important input variables for the CP discriminant, $ M_{\mathrm{t}\overline{\mathrm{t}}\mathrm{H}} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 4:
One of the most important input variables for the CP discriminant, $ \Delta \eta_{BB} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 4-a:
One of the most important input variables for the CP discriminant, $ \Delta \eta_{BB} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 4-b:
One of the most important input variables for the CP discriminant, $ \Delta \eta_{BB} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 4-c:
One of the most important input variables for the CP discriminant, $ \Delta \eta_{BB} $, in the three validation regions enriched from left to right in WZ, ttZ and misidentified lepton background.

png pdf
Figure 5:
Most important input variables to the XGBOOST used for CP discrimination in 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 5-a:
Most important input variables to the XGBOOST used for CP discrimination in 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 5-b:
Most important input variables to the XGBOOST used for CP discrimination in 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 5-c:
Most important input variables to the XGBOOST used for CP discrimination in 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 6:
Most important input variables to the XGBOOST used for CP discrimination in 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 6-a:
Most important input variables to the XGBOOST used for CP discrimination in 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 6-b:
Most important input variables to the XGBOOST used for CP discrimination in 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 6-c:
Most important input variables to the XGBOOST used for CP discrimination in 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ channel, defined in Table 4. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Figure 7:
Diagram showing the categorization strategy used for the signal extraction, making use of MVA-based algorithms and topological variables. In addition to the three signal regions (SRs), the ML fit receives input from two control regions (CRs).

png pdf
Figure 8:
Postfit discriminating distributions used as input to the fit. Events in the ttH node are categorized as described in Section 8 for the three categories: 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ (top) 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ (center) and 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ (bottom). For the 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ bl (bt) denotes events with less than (at least) two b-tagged jets. The ttH CP-even (red) and CP-odd (pink) contributions are determined from the fit. The contribution labeled as Nonprompt refers to the backgrounds arising from misidentified leptons while the label Charge mism. alludes to to the backgrounds arising from lepton charge mismeasurement.

png pdf
Figure 8-a:
Postfit discriminating distributions used as input to the fit. Events in the ttH node are categorized as described in Section 8 for the three categories: 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ (top) 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ (center) and 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ (bottom). For the 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ bl (bt) denotes events with less than (at least) two b-tagged jets. The ttH CP-even (red) and CP-odd (pink) contributions are determined from the fit. The contribution labeled as Nonprompt refers to the backgrounds arising from misidentified leptons while the label Charge mism. alludes to to the backgrounds arising from lepton charge mismeasurement.

png pdf
Figure 8-b:
Postfit discriminating distributions used as input to the fit. Events in the ttH node are categorized as described in Section 8 for the three categories: 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ (top) 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ (center) and 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ (bottom). For the 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ bl (bt) denotes events with less than (at least) two b-tagged jets. The ttH CP-even (red) and CP-odd (pink) contributions are determined from the fit. The contribution labeled as Nonprompt refers to the backgrounds arising from misidentified leptons while the label Charge mism. alludes to to the backgrounds arising from lepton charge mismeasurement.

png pdf
Figure 8-c:
Postfit discriminating distributions used as input to the fit. Events in the ttH node are categorized as described in Section 8 for the three categories: 2$\ell$SS$+$0$\tau_{\mathrm{h}}$ (top) 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ (center) and 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ (bottom). For the 2$\ell$SS$+$1$\tau_{\mathrm{h}}$ bl (bt) denotes events with less than (at least) two b-tagged jets. The ttH CP-even (red) and CP-odd (pink) contributions are determined from the fit. The contribution labeled as Nonprompt refers to the backgrounds arising from misidentified leptons while the label Charge mism. alludes to to the backgrounds arising from lepton charge mismeasurement.

png pdf
Figure 9:
Likelihood scan as a function of $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $: expected limits (left) and observed limits (right). The black cross shows the best value for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $ given by the fit. The black diamond shows the expected SM values for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $. Both 68 and 95% CL limits are shown. $ \kappa_{\text{V}} $ and H boson branching fractions are kept to their SM values.

png pdf
Figure 9-a:
Likelihood scan as a function of $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $: expected limits (left) and observed limits (right). The black cross shows the best value for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $ given by the fit. The black diamond shows the expected SM values for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $. Both 68 and 95% CL limits are shown. $ \kappa_{\text{V}} $ and H boson branching fractions are kept to their SM values.

png pdf
Figure 9-b:
Likelihood scan as a function of $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $: expected limits (left) and observed limits (right). The black cross shows the best value for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $ given by the fit. The black diamond shows the expected SM values for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $. Both 68 and 95% CL limits are shown. $ \kappa_{\text{V}} $ and H boson branching fractions are kept to their SM values.

png pdf
Figure 10:
Likelihood scan as a function of $ |f_{CP}^{\mathrm{H}\mathrm{t}\mathrm{t}}| $ for multilepton final estates. The solid (dashed) line shows the observed (expected) scan.

png pdf
Figure 11:
Likelihood scan as a function of $ |f_{CP}^{\mathrm{H}\mathrm{t}\mathrm{t}}| $. The left plot shows the expected likelihood scan for multilepton final states, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states, and the combination of multilepton, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states. The right plot shows the observed likelihood scan for multilepton final states and the combination of multilepton, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states.

png pdf
Figure 11-a:
Likelihood scan as a function of $ |f_{CP}^{\mathrm{H}\mathrm{t}\mathrm{t}}| $. The left plot shows the expected likelihood scan for multilepton final states, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states, and the combination of multilepton, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states. The right plot shows the observed likelihood scan for multilepton final states and the combination of multilepton, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states.

png pdf
Figure 11-b:
Likelihood scan as a function of $ |f_{CP}^{\mathrm{H}\mathrm{t}\mathrm{t}}| $. The left plot shows the expected likelihood scan for multilepton final states, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states, and the combination of multilepton, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states. The right plot shows the observed likelihood scan for multilepton final states and the combination of multilepton, $ \mathrm{H}\to\gamma\gamma $, and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ final states.

png pdf
Figure 12:
Likelihood scan as a function of $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $. Two-dimensional confidence intervals at 68% CL are depicted as shaded areas, for multilepton (red), the combination of $ \mathrm{H}\to\gamma\gamma $ and $ \mathrm{H}\to\mathrm{Z}\mathrm{Z} $ (blue), and the combination of the three channels (black). The 95% CL for the combination is show as a dashed line. The best fit for each is shown as a cross of the corresponding colour. The plot is symmetric with respect to the line $ \tilde{\kappa}_{\mathrm{t}} =$ 0, hence there are two points corresponding to the best fit, here we only show one for simplicity. The black diamond shows the SM expected value. The nontrivial correlation between the measurements are the source of the change in the best fit value and shape of the confidence regions. The coupling $ \kappa_{\text{V}} $ and the H boson branching fractions are kept to their SM values.
Tables

png pdf
Table 1:
Possible CP scenarios

png pdf
Table 2:
Standard model cross sections for the ttH and tH signals as well as for the most relevant background processes estimated from simulation. The cross sections are quoted for pp collisions at $ \sqrt{s} = $ 13 TeV.

png pdf
Table 3:
Event selections applied in the 2$\ell$SS$+$0$\tau_{\mathrm{h}}$, 2$\ell$SS$+$1$\tau_{\mathrm{h}}$, and 3$\ell$SS$+$0$\tau_{\mathrm{h}}$ categories.

png pdf
Table 4:
Input features for the three BDTs. A check mark indicates the variable is used in a given final state, whereas a long dash indicates the variable is not used in that final state.

png pdf
Table 5:
Summary of the uncertainty sources, their type, and their correlations across the three data-taking periods. Trigger efficiency uncertainty is taken as a shape or normalization systematic depending on the channel.

png pdf
Table 6:
One-dimensional confidence intervals at 68 and 95% CL for $ \kappa_{\mathrm{t}} $ (fixing $ \tilde{\kappa}_{\mathrm{t}} $ to the SM) and $ \tilde{\kappa}_{\mathrm{t}} $ (fixing $ \kappa_{\mathrm{t}} $ to the SM). The upper part of the table shows the expected limits while the lower part shows the observed limits.

png pdf
Table 7:
One-dimensional confidence intervals at 68 and 95% CL for $ \kappa_{\mathrm{t}} $ and $ \tilde{\kappa}_{\mathrm{t}} $.
Summary
A measurement of the charge-parity (CP) structure of the Yukawa coupling between the Higgs (H) boson and top quarks at tree level, when the H boson is produced in association with one (tH) or two (ttH) top quarks, is presented. The measurement is based on data collected in proton-proton collisions at $\sqrt{s} = $ 13 TeV by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 138 fb$^{-1}$. The analysis targets events where the H boson decays to leptons and the top quark(s) decay either leptonically or hadronically. Separation of CP-even from CP-odd scenarios is achieved by applying machine learning techniques to final states characterized by the presence of at least two leptons. Two-dimensional confidence regions are set on ${\kappa_{\mathrm{t}}}$ and ${\tilde{\kappa}_{\mathrm{t}}}$ which are respectively the CP-even and CP-odd top-Higgs Yukawa coupling modifiers: one-dimensional confidence intervals are also set, constraining ${\kappa_{\mathrm{t}}}$ to be within ($-$1.09, $-$0.74) or (0.77, 1.30) and ${\tilde{\kappa}_{\mathrm{t}}}$ to be within ($-$1.4, 1.4) at 95% confidence level (CL). No significant CP-odd contribution is observed, and the corresponding fraction parameter is determined to be ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} =$ 0.59 with an interval of (0.24, 0.81) at 68% CL. The results are combined with previously published analyses covering the H $\to$ ZZ and H $\to\gamma\gamma$ decay modes. Two- and one-dimensional confidence regions are set on ${\kappa_{\mathrm{t}}}$ and ${\tilde{\kappa}_{\mathrm{t}}}$, constraining ${\kappa_{\mathrm{t}}}$ to be within (0.86, 1.26) and ${\tilde{\kappa}_{\mathrm{t}}}$ to be within ($-$1.07, 1.07) at 95% CL. The possibility of a CP-odd contribution is also investigated in the combination, yielding a best fit of ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} =$ 0.28 with an interval of ${|{f_{\mathrm{CP}}^{\mathrm{H}\mathrm{t}\mathrm{t}}}|} <$ 0.55 at 68% CL. The results are compatible with predictions for the standard model H boson.
Additional Figures

png pdf
Additional Figure 1:
Output of the XGBOOST used for CP discrimination in 2$ \ell$SS+0$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Additional Figure 2:
Output of the XGBOOST used for CP discrimination in 3$ \ell$+0$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Additional Figure 3:
Output of the XGBOOST used for CP discrimination in 2$ \ell$SS+1$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Additional Figure 4:
Most important input variables to the XGBOOST used for CP discrimination in 2$ \ell$SS+1$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Additional Figure 4-a:
$M_{\mathrm{t\bar{t}H}}$, one of the most important input variables to the XGBOOST used for CP discrimination in 2$ \ell$SS+1$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Additional Figure 4-b:
Minimum $\Delta R_{\text{jet-leading lepton}}$, one of the most important input variables to the XGBOOST used for CP discrimination in 2$ \ell$SS+1$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.

png pdf
Additional Figure 4-c:
Average $\Delta R_{\text{jet-jet}}$, one of the most important input variables to the XGBOOST used for CP discrimination in 2$ \ell$SS+1$\tau_\mathrm{h} $ channel. The vertical bars represent the statistical uncertainty originating from the limited amount of simulated events. When not visible, the bars are smaller than the line width.
References
1 ATLAS Collaboration Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC PLB 716 (2012) 1 1207.7214
2 CMS Collaboration Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC PLB 716 (2012) 30 CMS-HIG-12-028
1207.7235
3 CMS Collaboration Search for resonances decaying to a pair of Higgs bosons in the $ \mathrm{b\overline{b}q\overline{q}'}\ell\nu $ final state in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JHEP 10 (2019) 125 1904.04193
4 CMS Collaboration Precise determination of the mass of the Higgs boson and tests of compatibility of its couplings with the standard model predictions using proton collisions at 7 and 8 TeV EPJC 75 (2015) 212 CMS-HIG-14-009
1412.8662
5 CMS Collaboration Combined measurements of Higgs boson couplings in proton--proton collisions at $ \sqrt{s}= $ 13 TeV EPJC 79 (2019) 421 CMS-HIG-17-031
1809.10733
6 CMS Collaboration A portrait of the Higgs boson by the CMS experiment ten years after the discovery Nature 607 (2022) 60 CMS-HIG-22-001
2207.00043
7 ATLAS Collaboration A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery Nature 607 (2022) 52 2207.00092
8 CMS Collaboration Measurement of the top quark mass using proton-proton data at $ {\sqrt{(s)}}= $ 7 and 8 TeV PRD 93 (2016) 072004 CMS-TOP-14-022
1509.04044
9 B. A. Dobrescu and C. T. Hill Electroweak symmetry breaking via top condensation seesaw PRL 81 (1998) 2634 hep-ph/9712319
10 R. S. Chivukula, B. A. Dobrescu, H. Georgi, and C. T. Hill Top Quark Seesaw Theory of Electroweak Symmetry Breaking PRD 59 (1999) 075003 hep-ph/9809470
11 D. Delepine, J. M. Gerard, and R. Gonzalez Felipe Is the standard Higgs scalar elementary? PLB 372 (1996) 271 hep-ph/9512339
12 CMS Collaboration Search for the associated production of the Higgs boson with a top-quark pair JHEP 09 (2014) 087 CMS-HIG-13-029
1408.1682
13 ATLAS Collaboration Search for the Standard Model Higgs boson produced in association with top quarks and decaying into $ \mathrm{b}\overline{\mathrm{b}} $ in pp collisions at $ \sqrt{s}= $ 8 TeV with the ATLAS detector EPJC 75 (2015) 349 1503.05066
14 ATLAS Collaboration Search for the Standard Model Higgs boson decaying into $ \mathrm{b}\overline{\mathrm{b}} $ produced in association with top quarks decaying hadronically in pp collisions at $ \sqrt{s}= $ 8 TeV with the ATLAS detector JHEP 05 (2016) 160 1604.03812
15 ATLAS Collaboration Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector PLB 749 (2015) 519 1506.05988
16 ATLAS Collaboration Search for $ \mathrm{H} \to \gamma\gamma $ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector PLB 740 (2015) 222 1409.3122
17 CMS Collaboration Measurements of properties of the Higgs boson decaying into the four-lepton final state in pp collisions at $ \sqrt{s}= $ 13 TeV JHEP 11 (2017) 047 CMS-HIG-16-041
1706.09936
18 ATLAS Collaboration Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector PRD 97 (2018) 072003 1712.08891
19 ATLAS Collaboration Search for the standard model Higgs boson produced in association with top quarks and decaying into a $ \mathrm{b}\overline{\mathrm{b}} $ pair in pp collisions at $ \sqrt{s} = $ 13 TeV with the ATLAS detector PRD 97 (2018) 072016 1712.08895
20 CMS Collaboration Evidence for associated production of a Higgs boson with a top quark pair in final states with electrons, muons, and hadronically decaying $ \tau $ leptons at $ \sqrt{s} = $ 13 TeV JHEP 08 (2018) 066 CMS-HIG-17-018
1803.05485
21 CMS Collaboration Search for $ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $ production in the all-jet final state in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JHEP 06 (2018) 101 CMS-HIG-17-022
1803.06986
22 CMS Collaboration Measurements of Higgs boson properties in the diphoton decay channel in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JHEP 11 (2018) 185 CMS-HIG-16-040
1804.02716
23 CMS Collaboration Search for $ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $ production in the $ \mathrm{H}\to\mathrm{b}\overline{\mathrm{b}} $ decay channel with leptonic $ \mathrm{t} \overline{\mathrm{t}} $ decays in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JHEP 03 (2019) 026 CMS-HIG-17-026
1804.03682
24 ATLAS Collaboration CP properties of Higgs boson interactions with top quarks in the $ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $ and $ \mathrm{t}\mathrm{H} $ processes using $ \mathrm{H}\to\gamma\gamma $ with the ATLAS detector PRL 125 (2020) 061802 2004.04545
25 CMS Collaboration Measurements of $ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $ 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
26 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 $ \sqrt{s} = $ 13 TeV EPJC 81 (2021) 378 CMS-HIG-19-008
2011.03652
27 CMS Collaboration Observation of $ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $ production PRL 120 (2018) 231801 CMS-HIG-17-035
1804.02610
28 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
29 CMS Collaboration Search for the associated production of a Higgs boson with a single top quark in proton-proton collisions at $ \sqrt{s}= $ 8 TeV JHEP 06 (2016) 177 CMS-HIG-14-027
1509.08159
30 CMS Collaboration Search for associated production of a Higgs boson and a single top quark in proton-proton collisions at $ \sqrt{s}= $ 13 TeV PRD 99 (2019) 092005 CMS-HIG-18-009
1811.09696
31 CMS Collaboration On the mass and spin-parity of the Higgs boson candidate via its decays to Z boson pairs PRL 110 (2013) 081803 CMS-HIG-12-041
1212.6639
32 CMS Collaboration Measurement of the properties of a Higgs boson in the four-lepton final state PRD 89 (2014) 092007 CMS-HIG-13-002
1312.5353
33 CMS Collaboration Constraints on the spin-parity and anomalous HVV couplings of the Higgs boson in proton collisions at 7 and 8 TeV PRD 92 (2015) 012004 CMS-HIG-14-018
1411.3441
34 CMS Collaboration Limits on the Higgs boson lifetime and width from its decay to four charged leptons PRD 92 (2015) 072010 CMS-HIG-14-036
1507.06656
35 CMS Collaboration Combined search for anomalous pseudoscalar HVV couplings in VH($ \mathrm{H}\to\mathrm{b}\overline{\mathrm{b}} $) production and $ \mathrm{H}\to\text{VV} $ decay PLB 759 (2016) 672 CMS-HIG-14-035
1602.04305
36 CMS Collaboration Constraints on anomalous Higgs boson couplings using production and decay information in the four-lepton final state PLB 775 (2017) 1 CMS-HIG-17-011
1707.00541
37 CMS Collaboration Constraints on anomalous HVV couplings from the production of Higgs bosons decaying to $ \tau $ lepton pairs PRD 100 (2019) 112002 CMS-HIG-17-034
1903.06973
38 ATLAS Collaboration Evidence for the spin-0 nature of the Higgs boson using ATLAS data PLB 726 (2013) 120 1307.1432
39 ATLAS Collaboration Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector EPJC 75 (2015) 476 1506.05669
40 ATLAS Collaboration Test of CP invariance in vector-boson fusion production of the Higgs boson using the Optimal Observable Method in the ditau decay channel with the ATLAS detector EPJC 76 (2016) 658 1602.04516
41 ATLAS Collaboration Measurement of inclusive and differential cross sections in the $ \mathrm{H} \to ZZ^* \to 4\ell $ decay channel in pp collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector JHEP 10 (2017) 132 1708.02810
42 ATLAS Collaboration Measurement of the Higgs boson coupling properties in the $ \mathrm{H}\to ZZ^{*} \to 4\ell $ decay channel at $ \sqrt{s} = $ 13 TeV with the ATLAS detector JHEP 03 (2018) 095 1712.02304
43 ATLAS Collaboration Measurements of Higgs boson properties in the diphoton decay channel with 36 fb$ ^{-1} $ of pp collision data at $ \sqrt{s} = $ 13 TeV with the ATLAS detector PRD 98 (2018) 052005 1802.04146
44 CMS Collaboration Constraints on anomalous Higgs boson couplings to vector bosons and fermions in its production and decay using the four-lepton final state PRD 104 (2021) 052004 CMS-HIG-19-009
2104.12152
45 CMS Collaboration Measurements of the Higgs boson width and anomalous HVV couplings from on-shell and off-shell production in the four-lepton final state PRD 99 (2019) 112003 CMS-HIG-18-002
1901.00174
46 C. Zhang and S. Willenbrock Effective-field-theory approach to top-quark production and decay PRD 83 (2011) 034006 1008.3869
47 R. Harnik et al. Measuring CP violation in $ h \to \tau^+ \tau^- $ at colliders PRD 88 (2013) 076009 1308.1094
48 T. Ghosh, R. Godbole, and X. Tata Determining the spacetime structure of bottom-quark couplings to spin-zero particles PRD 100 (2019) 015026 1904.09895
49 A. V. Gritsan, R. Röntsch, M. Schulze, and M. Xiao Constraining anomalous Higgs boson couplings to the heavy flavor fermions using matrix element techniques PRD 94 (2016) 055023 1606.03107
50 CMS Collaboration Analysis of the CP structure of the Yukawa coupling between the Higgs boson and $ \tau $ leptons in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JHEP 06 (2022) 012 CMS-HIG-20-006
2110.04836
51 CMS Collaboration Constraints on anomalous Higgs boson couplings to vector bosons and fermions from the production of Higgs bosons using the $ \tau\tau $ final state accepted by PRD, 2022 2205.05120
52 ATLAS Collaboration Constraints on Higgs boson properties using $ WW^{*}(\to \mathrm{e}\nu\mu\nu)\text{jj} $ production in 36.1 fb$ ^{-1} $ of $ \sqrt{s}= $ 13 TeV pp collisions with the ATLAS detector 2109.13808
53 D. de Florian et al. Handbook of LHC Higgs cross sections: 4. Deciphering the nature of the Higgs sector CERN Report CERN-2017-002-M, 2016
link
1610.07922
54 ATLAS, CMS Collaboration Combined Measurement of the Higgs Boson Mass in $ pp $ Collisions at $ \sqrt{s}= $ 7 and 8 TeV with the ATLAS and CMS Experiments PRL 114 (2015) 191803 1503.07589
55 K. Kondo Dynamical likelihood method for reconstruction of events with missing momentum. 1: method and toy models J. Phys. Soc. Jap. 57 (1988) 4126
56 K. Kondo Dynamical likelihood method for reconstruction of events with missing momentum. 2: mass spectra for 2 $ \to $ 2 processes J. Phys. Soc. Jap. 60 (1991) 836
57 CMS Collaboration HEPData record for this analysis link
58 F. Demartin, F. Maltoni, K. Mawatari, and M. Zaro Higgs production in association with a single top quark at the LHC EPJC 75 (2015) 267 1504.00611
59 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
60 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004
61 CMS Collaboration Precision luminosity measurement in proton-proton collisions at $ \sqrt{s} = $ 13 TeV in 2015 and 2016 at CMS EPJC 81 (2021) 800 CMS-LUM-17-003
2104.01927
62 CMS Collaboration CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2018
link
CMS-PAS-LUM-17-004
63 CMS Collaboration CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2019
link
CMS-PAS-LUM-18-002
64 F. Maltoni, G. Ridolfi, and M. Ubiali b-initiated processes at the LHC: a reappraisal JHEP 07 (2012) 022 1203.6393
65 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
66 J. Alwall et al. Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions EPJC 53 (2008) 473 0706.2569
67 P. Artoisenet, R. Frederix, O. Mattelaer, and R. Rietkerk Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations JHEP 03 (2013) 015 1212.3460
68 R. Frederix and S. Frixione Merging meets matching in MC@NLO JHEP 12 (2012) 061 1209.6215
69 R. Frederix and I. Tsinikos Subleading EW corrections and spin-correlation effects in $ t\bar{t}W $ multi-lepton signatures EPJC 80 (2020) 803 2004.09552
70 J. A. Dror, M. Farina, E. Salvioni, and J. Serra Strong tW Scattering at the LHC JHEP 01 (2016) 071 1511.03674
71 P. Nason A new method for combining NLO QCD with shower Monte Carlo algorithms JHEP 11 (2004) 040 hep-ph/0409146
72 S. Frixione, P. Nason, and C. Oleari Matching NLO QCD computations with parton shower simulations: the POWHEG method JHEP 11 (2007) 070 0709.2092
73 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
74 T. Sjöstrand et al. An introduction to PYTHIA 8.2 Comput. Phys. Commun. 191 (2015) 159 1410.3012
75 CMS Collaboration Extraction and validation of a new set of CMS PYTHIA 8 tunes from underlying-event measurements EPJC 80 (2020) 4 CMS-GEN-17-001
1903.12179
76 CMS Collaboration Investigations of the impact of the parton shower tuning in PYTHIA 8 in the modelling of $ \mathrm{t} \overline{\mathrm{t}} $ at $ \sqrt{s}= $ 8 and 13 TeV Technical Report, 2016
CMS-PAS-TOP-16-021
CMS-PAS-TOP-16-021
77 CMS Collaboration Event generator tunes obtained from underlying event and multiparton scattering measurements EPJC 76 (2016) 155 CMS-GEN-14-001
1512.00815
78 J. S. Gainer et al. Exploring theory space with Monte Carlo reweighting JHEP 10 (2014) 078 1404.7129
79 O. Mattelaer On the maximal use of Monte Carlo samples: re-weighting events at NLO accuracy EPJC 76 (2016) 674 1607.00763
80 GEANT4 Collaboration GEANT 4---a simulation toolkit NIM A 506 (2003) 250
81 J. Allison et al. Recent developments in GEANT 4 NIM A 835 (2016) 186
82 CMS Collaboration Measurements of inclusive W and Z cross sections in pp collisions at $ \sqrt{s} = $ 7 TeV JHEP 01 (2011) 080 CMS-EWK-10-002
1012.2466
83 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
84 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
85 CMS Collaboration Performance of reconstruction and identification of $ \tau $ leptons decaying to hadrons and $ \nu_{\tau} $ in pp collisions at $ \sqrt{s} = $ 13 TeV JINST 13 (2018) P10005 CMS-TAU-16-003
1809.02816
86 CMS Collaboration Performance of missing transverse momentum reconstruction in proton-proton collisions at $ \sqrt{s} = $ 13 TeV using the CMS detector JINST 14 (2019) P07004 CMS-JME-17-001
1903.06078
87 F. Demartin et al. $ \mathrm{t}\mathrm{W}\mathrm{H} $ associated production at the LHC EPJC 77 (2017) 34 1607.05862
88 J. M. Campbell, R. K. Ellis, and C. Williams Vector boson pair production at the LHC JHEP 07 (2011) 018 1105.0020
89 CMS Collaboration Identification of hadronic tau lepton decays using a deep neural network CMS-TAU-20-001
2201.08458
90 M. Cacciari, G. P. Salam, and G. Soyez The anti-$ k_{\mathrm{T}} $ jet clustering algorithm JHEP 04 (2008) 063 0802.1189
91 CMS Collaboration Particle-flow reconstruction and global event description with the CMS detector JINST 12 (2017) P10003 CMS-PRF-14-001
1706.04965
92 M. Cacciari, G. P. Salam, and G. Soyez The catchment area of jets JHEP 04 (2008) 005 0802.1188
93 CMS Collaboration Technical proposal for the Phase-II upgrade of the Compact Muon Solenoid CMS Technical Proposal CERN-LHCC-2015-010, CMS-TDR-15-02, 2015
CDS
94 E. Bols et al. Jet Flavour Classification Using DeepJet JINST 15 (2020) P12012 2008.10519
95 CMS Collaboration Performance of the DeepJet b tagging algorithm using 41.9/fb of data from proton-proton collisions at 13 TeV with Phase 1 CMS detector CMS Detector Performance Note CMS-DP-2018-058, 2018
CDS
96 T. Hastie, R. Tibshirani, and J. Friedman The elements of statistical learning Springer-Verlag, second edition, ISBN~978-0-387-84858-7, 2013
link
97 L. Breiman, J. Friedman, R. Olshen, and C. Stone Classification and regression trees Wadsworth, . ISBN~978-041418, 1984
98 J. Brehmer, K. Cranmer, G. Louppe, and J. Pavez Constraining effective field theories with machine learning PRL 121 (2018) 111801 1805.00013
99 CMS Collaboration Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at $ \sqrt{s} = $ 8 TeV JINST 10 (2015) P06005 CMS-EGM-13-001
1502.02701
100 T. Chen and C. Guestrin XGBoost: A scalable tree boosting system link 1603.02754
101 F. Demartin et al. Higgs characterisation at NLO in QCD: CP properties of the top-quark Yukawa interaction EPJC 74 (2014) 3065 1407.5089
102 ATLAS and CMS Collaborations, and LHC Higgs Combination Group Procedure for the LHC Higgs boson search combination in Summer 2011 Technical Report CMS-NOTE-2011-005, ATL-PHYS-PUB-2011-11, 2011
103 R. J. Barlow and C. Beeston Fitting using finite Monte Carlo samples Comput. Phys. Commun. 77 (1993) 219
104 CMS Collaboration Measurement of the inelastic proton-proton cross section at $ \sqrt{s}= $ 13 TeV JHEP 07 (2018) 161 CMS-FSQ-15-005
1802.02613
105 CMS Collaboration Performance of the CMS Level-1 trigger in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JINST 15 (2020) P10017 CMS-TRG-17-001
2006.10165
106 S. Heinemeyer et al. Handbook of LHC Higgs cross sections: 3. Higgs properties CERN Report CERN-2013-004, 2013
link
1307.1347
107 M. Cacciari et al. The $ \mathrm{t}\overline{\mathrm{t}} $ cross-section at 1.8 TeV and 1.96 TeV: a study of the systematics due to parton densities and scale dependence JHEP 04 (2004) 068 hep-ph/0303085
108 S. Catani, D. de Florian, M. Grazzini, and P. Nason Soft gluon resummation for Higgs boson production at hadron colliders JHEP 07 (2003) 028 hep-ph/0306211
109 R. Frederix et al. Four-lepton production at hadron colliders: MadGraph-5_aMC@NLO predictions with theoretical uncertainties JHEP 02 (2012) 099 1110.4738
110 J. Butterworth et al. PDF4LHC recommendations for LHC Run 2 JPG 43 (2016) 023001 1510.03865
Compact Muon Solenoid
LHC, CERN