CMS-PAS-HIG-19-008 | ||
Higgs boson production in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at $\sqrt{s} = $ 13 TeV | ||
CMS Collaboration | ||
July 2020 | ||
Abstract: The rate for Higgs (H) bosons production in association with either one ($\mathrm{t}\mathrm{H}$) or two ($\mathrm{t}\bar{\mathrm{t}}\mathrm{H}$) top quarks is measured in final states with multiple electrons, muons, and hadronically decaying $\tau$ leptons, using proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the CMS experiment. The analyzed data set corresponds to an integrated luminosity of 137 fb$^{-1}$. The analysis targets events where the H boson decays via $\mathrm{H} \to \mathrm{W}\mathrm{W}$, $\mathrm{H} \to \tau\tau$, or $\mathrm{H} \to \mathrm{Z}\mathrm{Z}$ and the top quark(s) decay either leptonically or hadronically. The signal yield is maximized by including ten different signatures in the analysis depending on the lepton multiplicity. The separation of the H boson signal from backgrounds is enhanced by machine learning techniques and matrix element methods. The measured production rates for the $\mathrm{t}\bar{\mathrm{t}}\mathrm{H}$ and $\mathrm{t}\mathrm{H}$ signals amount to 0.92 $\pm$ 0.19 (stat) $^{+0.17}_{-0.13}$ (syst) and 5.7 $\pm$ 2.7 (stat) $\pm$ 3.0 (syst) times their respective standard model (SM) expectations. Assuming that the H boson coupling to the $\tau$ lepton is equal in strength to the values expected in the SM, the coupling $y_{\mathrm{t}}$ of the H boson to the top quark is constrained, at 95% confidence level, to be within $-0.9 < y_{\mathrm{t}} < -0.7$ or $ 0.7 < y_{\mathrm{t}} < 1.1$ times the SM expectation for this coupling. | ||
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These preliminary results are superseded in this paper, EPJC 81 (2021) 378. The superseded preliminary plots can be found here. |
Figures & Tables | Summary | Additional Figures | References | CMS Publications |
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Figures | |
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Figure 1:
Feynman diagrams at LO for $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ production. |
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Figure 1-a:
Feynman diagram at LO for $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ production. |
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Figure 1-b:
Feynman diagram at LO for $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ production. |
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Figure 2:
Feynman diagrams at LO for $ {{\mathrm{t}} {\mathrm{H}}}$ production via the $t$-channel ($ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{q}}}$; upper left, upper right) and $s$-channel (center) processes and for the associated production of a $ {\mathrm{H}}$ boson with a single top quark and a $\mathrm{W} $ boson ($ {{{\mathrm{t}} {\mathrm{H}}}\mathrm{W}}$; lower left, lower right). The $ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{q}}}$ and $ {{{\mathrm{t}} {\mathrm{H}}}\mathrm{W}}$ production processes are shown for the 5FS. |
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Figure 2-a:
Feynman diagram at LO for $ {{\mathrm{t}} {\mathrm{H}}}$ production via the $t$-channel ($ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{q}}}$. |
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Figure 2-b:
Feynman diagram at LO for $ {{\mathrm{t}} {\mathrm{H}}}$ production via the $t$-channel ($ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{q}}}$. |
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Figure 2-c:
Feynman diagram at LO for $ {{\mathrm{t}} {\mathrm{H}}}$ production via the $s$-channel ($ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{b}}}$. |
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Figure 2-d:
Feynman diagram at LO for the associated production of a $ {\mathrm{H}}$ boson with a single top quark and a $\mathrm{W} $ boson ($ {{{\mathrm{t}} {\mathrm{H}}}\mathrm{W}}$). |
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Figure 2-e:
Feynman diagram at LO for the associated production of a $ {\mathrm{H}}$ boson with a single top quark and a $\mathrm{W} $ boson ($ {{{\mathrm{t}} {\mathrm{H}}}\mathrm{W}}$). |
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Figure 3:
Transverse momentum (left) and pseudorapidity (center) distribution of bottom quarks in $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal events compared to $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets background events, and multiplicity of jets passing tight b jet identification criteria (right). The latter distribution is shown separately for $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets background events in which a non-prompt lepton is misidentified as a prompt lepton and for those background events in which all reconstructed leptons are prompt leptons. The events are selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel. |
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Figure 3-a:
Transverse momentum distribution of bottom quarks in $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal events compared to $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets background events. The events are selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel. |
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Figure 3-b:
Pseudorapidity distribution of bottom quarks in $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal events compared to $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets background events. The events are selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel. |
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Figure 3-c:
Multiplicity of jets passing tight b jet identification criteria. The distribution is shown separately for $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets background events in which a non-prompt lepton is misidentified as a prompt lepton and for those background events in which all reconstructed leptons are prompt leptons. The events are selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel. |
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Figure 4:
Distributions in $ {{m_{\mathrm {T}}} ^{{\text {fix}}}}$ for events containing an electron candidate of 25 $ < {p_{\mathrm {T}}} < $ 35 GeV in the ECAL barrel, which (left) passes the nominal selection and (right) passes the relaxed, but fails the nominal selection. The "electroweak'' (EWK) background refers to the sum of W+jets, DY and diboson production. The "rare'' background is defined in the text. The data in the fail sample agrees with the sum of multijet, EWK, $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets, and "rare'' backgrounds by construction, as the number of multijet events in the fail sample is computed by the subtracting the sum of EWK, $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets, and "rare'' background contributions from the data. The FF contribution is derived separately for each era: this figure shows, as an example, the results obtained with the 2017 data set. The uncertainty band represents the uncertainty after the fit has been performed. |
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Figure 4-a:
Distribution in $ {{m_{\mathrm {T}}} ^{{\text {fix}}}}$ for events containing an electron candidate of 25 $ < {p_{\mathrm {T}}} < $ 35 GeV in the ECAL barrel, which passes the nominal selection. The "electroweak'' (EWK) background refers to the sum of W+jets, DY and diboson production. The "rare'' background is defined in the text. The data in the fail sample agrees with the sum of multijet, EWK, $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets, and "rare'' backgrounds by construction, as the number of multijet events in the fail sample is computed by the subtracting the sum of EWK, $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets, and "rare'' background contributions from the data. The FF contribution is derived separately for each era: this figure shows, as an example, the results obtained with the 2017 data set. The uncertainty band represents the uncertainty after the fit has been performed. |
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Figure 4-b:
Distribution in $ {{m_{\mathrm {T}}} ^{{\text {fix}}}}$ for events containing an electron candidate of 25 $ < {p_{\mathrm {T}}} < $ 35 GeV in the ECAL barrel, which passes the relaxed, but fails the nominal selection. The "electroweak'' (EWK) background refers to the sum of W+jets, DY and diboson production. The "rare'' background is defined in the text. The data in the fail sample agrees with the sum of multijet, EWK, $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets, and "rare'' backgrounds by construction, as the number of multijet events in the fail sample is computed by the subtracting the sum of EWK, $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets, and "rare'' background contributions from the data. The FF contribution is derived separately for each era: this figure shows, as an example, the results obtained with the 2017 data set. The uncertainty band represents the uncertainty after the fit has been performed. |
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Figure 5:
Distributions in ${p_{\mathrm {T}}}$ of non-prompt (left) electrons and (right) muons in simulated $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets events, for the three cases "nominal'', "relaxed, $f_{i}$ from $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets'', and "relaxed, $f_{i}$ from multijet'' discussed in text. The figure illustrates that a non-closure correction needs to be applied to the probabilities $f_{i}$ measured for electrons in data, while no such correction is needed for muons. |
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Figure 5-a:
Distribution in ${p_{\mathrm {T}}}$ of non-prompt electrons in simulated $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets events, for the three cases "nominal'', "relaxed, $f_{i}$ from $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets'', and "relaxed, $f_{i}$ from multijet'' discussed in text. The figure illustrates that a non-closure correction needs to be applied to the probabilities $f_{i}$ measured for electrons in data, while no such correction is needed for muons. |
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Figure 5-b:
Distribution in ${p_{\mathrm {T}}}$ of non-prompt muons in simulated $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets events, for the three cases "nominal'', "relaxed, $f_{i}$ from $ {{\mathrm{t}} {\mathrm{\bar{t}}}}$+jets'', and "relaxed, $f_{i}$ from multijet'' discussed in text. The figure illustrates that a non-closure correction needs to be applied to the probabilities $f_{i}$ measured for electrons in data, while no such correction is needed for muons. |
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Figure 6:
Distributions in $m_{\mathrm{e} \mathrm{e}}$ for electron pairs of (left) SS and (right) OS charge in $ {{\mathrm{Z} /\gamma ^{*}} \to \mathrm{e} \mathrm{e}}$ candidate events in which both electrons are in the ECAL barrel and have transverse momenta within the range 25 $ < {p_{\mathrm {T}}} < $ 50 GeV, for data recorded in 2018 compared to the expectation. Uncertainties shown include statistical uncertainties. |
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Figure 6-a:
Distribution in $m_{\mathrm{e} \mathrm{e}}$ for electron pairs of SS charge in $ {{\mathrm{Z} /\gamma ^{*}} \to \mathrm{e} \mathrm{e}}$ candidate events in which both electrons are in the ECAL barrel and have transverse momenta within the range 25 $ < {p_{\mathrm {T}}} < $ 50 GeV, for data recorded in 2018 compared to the expectation. Uncertainties shown include statistical uncertainties. |
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Figure 6-b:
Distribution in $m_{\mathrm{e} \mathrm{e}}$ for electron pairs of OS charge in $ {{\mathrm{Z} /\gamma ^{*}} \to \mathrm{e} \mathrm{e}}$ candidate events in which both electrons are in the ECAL barrel and have transverse momenta within the range 25 $ < {p_{\mathrm {T}}} < $ 50 GeV, for data recorded in 2018 compared to the expectation. Uncertainties shown include statistical uncertainties. |
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Figure 7:
Distributions in the activation value of the ANN output node with the highest activation value for events selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal (upper left), $ {{\mathrm{t}} {\mathrm{H}}}$ signal (upper right), $ {{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{W}}$ background (lower left), and other background (lower right). The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 7-a:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 7-b:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{H}}}$ signal. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 7-c:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{W}}$ background. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 7-d:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 2${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as other backgrounds. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 8:
Distributions in the activation value of the ANN output node with the highest activation value for events selected in the 3${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal (upper left), $ {{\mathrm{t}} {\mathrm{H}}}$ signal (upper right), and background (lower left), and for events selected in the 2${\ell}$ ss+1${\tau _{\mathrm {h}}}$ channel (lower right). In case of the 2${\ell}$ ss+1${\tau _{\mathrm {h}}}$ channel, the activation value of the ANN output nodes for $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal, $ {{\mathrm{t}} {\mathrm{H}}}$ signal, and background are shown together in a single histogram, concatenating histogram bins as appropriate and enumerating the bins by a monotonously increasing number. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 8-a:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 3${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 8-b:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 3${\ell}$+0${\tau _{\mathrm {h}}}$ channel and classified as $ {{\mathrm{t}} {\mathrm{H}}}$ signal. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 8-c:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 3${\ell}$+0${\tau _{\mathrm {h}}}$ channel $ {{\mathrm{t}} {\mathrm{H}}}$ background. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 8-d:
Distribution in the activation value of the ANN output node with the highest activation value for events selected in the 2${\ell}$ ss+1${\tau _{\mathrm {h}}}$ channel. The activation value of the ANN output nodes for $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal, $ {{\mathrm{t}} {\mathrm{H}}}$ signal, and background are shown together in a single histogram, concatenating histogram bins as appropriate and enumerating the bins by a monotonously increasing number. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 9:
Distributions in BDT output for events selected in the 2${\ell}$ os+1${\tau _{\mathrm {h}}}$ (upper left), 3${\ell}$+1${\tau _{\mathrm {h}}}$ (upper right), and 4${\ell}$+0${\tau _{\mathrm {h}}}$ (lower) channels. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 9-a:
Distribution in BDT output for events selected in the 2${\ell}$ os+1${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 9-b:
Distribution in BDT output for events selected in the 3${\ell}$+1${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 9-c:
Distribution in BDT output for events selected in the 4${\ell}$+0${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 10:
Distributions in BDT output used for the signal extraction in the 0${\ell}$+2${\tau _{\mathrm {h}}}$ (upper left), 1${\ell}$+1${\tau _{\mathrm {h}}}$ (upper right), 1${\ell}$+2${\tau _{\mathrm {h}}}$ (lower left), and 2${\ell}$+2${\tau _{\mathrm {h}}}$ (lower right) channels. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 10-a:
Distribution in BDT output used for the signal extraction in the 0${\ell}$+2${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 10-b:
Distribution in BDT output used for the signal extraction in the 1${\ell}$+1${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 10-c:
Distribution in BDT output used for the signal extraction in the 1${\ell}$+2${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 10-d:
Distribution in BDT output used for the signal extraction in the 2${\ell}$+2${\tau _{\mathrm {h}}}$ channel. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 11:
Distributions in discriminating observables in the 3${\ell}$+0${\tau _{\mathrm {h}}}$ (left) and 4${\ell}$+0${\tau _{\mathrm {h}}}$ (right) control region. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 11-a:
Distribution in discriminating observables in the 3${\ell}$+0${\tau _{\mathrm {h}}}$ control region. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 11-b:
Distribution in discriminating observables in the 4${\ell}$+0${\tau _{\mathrm {h}}}$ control region. The distributions expected for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals and for background processes are shown for the values of the POI and of the nuisance parameters obtained from the ML fit. The best-fit value of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ production rates amounts to $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92 and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7 times the rates expected in the SM. |
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Figure 12:
Distribution in the decimal logarithm of the ratio between the expected $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}+ {{\mathrm{t}} {\mathrm{H}}}$ signal and the expected sum of background contributions in each bin of the $105$ distributions that are included in the ML fit used for the signal extraction. The distributions expected for signal and background processes are computed for $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}} = $ 0.92, $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}} = $ 5.7, and the values of nuisance parameters obtained from the ML fit. |
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Figure 13:
Production rate $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}}$ of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal (left) and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}}$ of $ {{\mathrm{t}} {\mathrm{H}}}$ signal (right), in units of their rate of production expected in the SM, measured in each of the ten channels individually and for the combination of all channels. The signal strength in the 2${\ell}$+2$\tau_{\mathrm{h}}$ is constrained to be greater than zero. |
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Figure 13-a:
Production rate $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}}$ of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ signal, in units of their rate of production expected in the SM, measured in each of the ten channels individually and for the combination of all channels. The signal strength in the 2${\ell}$+2$\tau_{\mathrm{h}}$ is constrained to be greater than zero. |
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Figure 13-b:
Production rate $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}}$ of the $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}}$ of $ {{\mathrm{t}} {\mathrm{H}}}$ signal, in units of their rate of production expected in the SM, measured in each of the ten channels individually and for the combination of all channels. The signal strength in the 2${\ell}$+2$\tau_{\mathrm{h}}$ is constrained to be greater than zero. |
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Figure 14:
Two-dimensional contours of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of the production rates of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals ($ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}}$ and $ {\hat{\mu}}_{{{\mathrm{t}} {\mathrm{H}}}}$) and of the $ {{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{Z}}$ and $ {{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{W}}$ backgrounds ($\theta _{{{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{Z}}}$ and $\theta _{{{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{W}}}$). The two production rates that are not shown on either the $x$ or the $y$ axis are profiled such that the function $\mathcal {L}$ attains its minimum at each point in the $x$-$y$ plane. |
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Figure 14-a:
Two-dimensional contour of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of the production rates of the |
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Figure 14-b:
Two-dimensional contour of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of the production rates of the |
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Figure 14-c:
Two-dimensional contour of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of the production rates of the |
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Figure 14-d:
Two-dimensional contour of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of the production rates of the |
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Figure 15:
Probability for $ {{\mathrm{t}} {\mathrm{H}}}$ signal events produced by the $ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{q}}}$ (left) and $ {{{\mathrm{t}} {\mathrm{H}}}\mathrm{W}}$ (right) production process to pass the event selection criteria for the 2${\ell}$+0${\tau _{\mathrm {h}}}$, 3${\ell}$+0${\tau _{\mathrm {h}}}$, and 2${\ell}$+1${\tau _{\mathrm {h}}}$ channels in each of the $ {\mathrm{H}}$ boson decay modes as a function of the ratio $ {\kappa _{{\mathrm{t}}}}/ {\kappa _{\mathrm {V}}}$ of the $ {\mathrm{H}}$ boson couplings to the top quark and to the $\mathrm{W} $ boson. |
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Figure 15-a:
Probability for $ {{\mathrm{t}} {\mathrm{H}}}$ signal events produced by the $ {{{\mathrm{t}} {\mathrm{H}}} {\mathrm{q}}}$ production process to pass the event selection criteria for the 2${\ell}$+0${\tau _{\mathrm {h}}}$, 3${\ell}$+0${\tau _{\mathrm {h}}}$, and 2${\ell}$+1${\tau _{\mathrm {h}}}$ channels in each of the $ {\mathrm{H}}$ boson decay modes as a function of the ratio $ {\kappa _{{\mathrm{t}}}}/ {\kappa _{\mathrm {V}}}$ of the $ {\mathrm{H}}$ boson couplings to the top quark and to the $\mathrm{W} $ boson. |
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Figure 15-b:
Probability for $ {{\mathrm{t}} {\mathrm{H}}}$ signal events produced by the $ {{{\mathrm{t}} {\mathrm{H}}}\mathrm{W}}$ production process to pass the event selection criteria for the 2${\ell}$+0${\tau _{\mathrm {h}}}$, 3${\ell}$+0${\tau _{\mathrm {h}}}$, and 2${\ell}$+1${\tau _{\mathrm {h}}}$ channels in each of the $ {\mathrm{H}}$ boson decay modes as a function of the ratio $ {\kappa _{{\mathrm{t}}}}/ {\kappa _{\mathrm {V}}}$ of the $ {\mathrm{H}}$ boson couplings to the top quark and to the $\mathrm{W} $ boson. |
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Figure 16:
Variation of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of $ {\kappa _{{\mathrm{t}}}}$, profiling over $ {\kappa _{\mathrm {V}}}$ (left), and as a function of $ {\kappa _{{\mathrm{t}}}}$ and $ {\kappa _{\mathrm {V}}}$ (right). |
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Figure 16-a:
Variation of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of $ {\kappa _{{\mathrm{t}}}}$, profiling over $ {\kappa _{\mathrm {V}}}$. |
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Figure 16-b:
Variation of the likelihood function $\mathcal {L}$, given by Eq. (3), as a function of $ {\kappa _{{\mathrm{t}}}}$ and $ {\kappa _{\mathrm {V}}}$. |
Tables | |
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Table 1:
Standard model cross sections for the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals as well as for the most relevant background processes. The cross sections are quoted for ${\mathrm{p}} {\mathrm{p}} $ collisions at $\sqrt {s} = $ 13 TeV. The quoted value for DY production includes a generator-level requirement of $m_{\mathrm{Z} /\gamma ^*} > $ 50 GeV. |
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Table 2:
Event selections applied in the 2${\ell}$+0${\tau _{\mathrm {h}}}$, 2${\ell}$+1${\tau _{\mathrm {h}}}$, 3${\ell}$+0${\tau _{\mathrm {h}}}$, and 3${\ell}$+1${\tau _{\mathrm {h}}}$ channels. The ${p_{\mathrm {T}}}$ thresholds applied to the lepton of highest, second highest, and third highest ${p_{\mathrm {T}}}$ are separated by slashes. The symbol "---'' indicates that no requirement is applied on the feature. |
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Table 3:
Event selections applied in the 0${\ell}$+2${\tau _{\mathrm {h}}}$, 1${\ell}$+1${\tau _{\mathrm {h}}}$, 1${\ell}$+2${\tau _{\mathrm {h}}}$, and 2${\ell}$+2${\tau _{\mathrm {h}}}$ channels. The ${p_{\mathrm {T}}}$ thresholds applied to the lepton and to the $ {\tau _\mathrm {h}} $ of highest and second highest ${p_{\mathrm {T}}}$ are separated by slashes. The symbol "---'' indicates that no requirement is applied on the feature. |
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Table 4:
Event selections applied in the 2${\ell}$+1${\tau _{\mathrm {h}}}$ and 4${\ell}$+0${\tau _{\mathrm {h}}}$ channels. The symbol "---'' indicates that no requirement is applied on the feature. |
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Table 5:
Input variables to the multivariant discriminants in each of the ten analysis channels. The symbol "---'' indicates that the variable is not considered. |
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Table 6:
Number of events selected in the 3${\ell}$- and 4${\ell}$-CRs and in the CR for the $ {{\mathrm{t}} {\mathrm{\bar{t}}}\mathrm{W} (\mathrm{W})}$ background, compared to the event yields expected from different types of background and from the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ and $ {{\mathrm{t}} {\mathrm{H}}}$ signals, after the fit to data is performed as described in 9. Uncertainties shown include all systematic components. |
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Table 7:
Summary of the main sources of systematic uncertainty and their impact on the measurement of the $ {{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}$ plus $ {{\mathrm{t}} {\mathrm{H}}}$ signal rate $ {\mu}_{{{\mathrm{t}} {\mathrm{\bar{t}}} {\mathrm{H}}}+ {{\mathrm{t}} {\mathrm{H}}}}$ and the measured value of the unconstrained nuisance parameters. The quantity $\Delta {\mu}_{x}/ {\mu}_{x}$ corresponds to the change in uncertainty when fixing the nuisance parameters associated to that uncertainty in the fit. Under the label "MC and sideband statistical uncertainty'' are the uncertainties associated to the limited number of simulated MC events and the amount of data events in the application region of the FF method. |
Summary |
The rate for Higgs boson production in association with either one or two top quarks has been measured in events containing multiple electrons, muons, and hadronically decaying tau leptons, using data recorded by the CMS experiment in pp collisions at $\sqrt{s} = $ 13 TeV in 2016, 2017, and 2018. The analyzed data set corresponds to an integrated luminosity of 137 fb$^{-1}$. Ten different experimental signatures are considered in the analysis, differing by the multiplicity of e, $\mu$, and ${\tau_\mathrm{h}}$ and targeting events in which the Higgs boson decays via $\mathrm{H} \to \mathrm{W}\mathrm{W}$, $\mathrm{H} \to \tau\tau$, or $\mathrm{H} \to \mathrm{Z}\mathrm{Z}$, while the top quark(s) decay either leptonically or hadronically. The measured production rates for the ${\mathrm{t}}{\mathrm{\bar{t}}}\mathrm{H}$ and ${\mathrm{t}}\mathrm{H}$ signals amount to 0.92 $\pm$ 0.19 (stat) $^{+0.17}_{-0.13}$ (syst) and 5.7 $\pm$ 2.7 (stat) $\pm$ 3.0 (syst) times their respective standard model (SM) expectations. Assuming that the H boson coupling to the $\tau$ lepton is equal in strength to the values expected in the SM, the coupling $y_{{\mathrm{t}}}$ of the H boson to the top quark is constrained, at 95% confidence level, to be within $-0.9 < y_{{\mathrm{t}}} < -0.7$ or $ 0.7 < y_{{\mathrm{t}}} < 1.1$ times the SM expectation for this coupling. |
Additional Figures | |
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Additional Figure 1:
Relative contribution from signal production and decay mode to each of the signal regions. |
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Additional Figure 2:
Variation of the likelihood function $\mathcal {L}$ as a function of $\kappa _{{\mathrm {t}}}$, after fixing $\kappa _{\mathrm{V}}$ to its SM value. |
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Additional Figure 3:
Number of expected signal and background events in each one of the analysis categories. |
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Additional Figure 4:
Display of a $ {\mathrm {t}} {\overline {\mathrm {t}}} {\mathrm {H}} $ candidate event in the 2$\ell$+0${{\tau} _\mathrm {h}} $ region. The event features two negative-sign charge muons, six jets and no additional ${{\tau} _\mathrm {h}}$. |
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Additional Figure 5:
Display of a $ {\mathrm {t}} {\overline {\mathrm {t}}} {\mathrm {H}} $ candidate event in the 2$\ell$+0${{\tau} _\mathrm {h}} $ region. The event features two negative-sign charge muons, six jets and no additional ${{\tau} _\mathrm {h}}$. |
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Compact Muon Solenoid LHC, CERN |
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