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| CMS-HIG-17-002 ; CERN-EP-2017-126 | ||
| Search for Higgs boson pair production in events with two bottom quarks and two tau leptons in proton-proton collisions at $ \sqrt{s} = $ 13 TeV | ||
| CMS Collaboration | ||
| 10 July 2017 | ||
| Phys. Lett. B 778 (2018) 101 | ||
| Abstract: A search for the production of Higgs boson pairs in proton-proton collisions at a centre-of-mass energy of 13 TeV is presented, using a data sample corresponding to an integrated luminosity of 35.9 fb$^{-1}$ collected with the CMS detector at the LHC. Events with one Higgs boson decaying into two bottom quarks and the other decaying into two $\tau$ leptons are explored to investigate both resonant and nonresonant production mechanisms. The data are found to be consistent, within uncertainties, with the standard model background predictions. For resonant production, upper limits at the 95% confidence level are set on the production cross section for Higgs boson pairs as a function of the hypothesized resonance mass and are interpreted in the context of the minimal supersymmetric standard model. For nonresonant production, upper limits on the production cross section constrain the parameter space for anomalous Higgs boson couplings. The observed (expected) upper limit at 95% confidence level corresponds to about 30 (25) times the prediction of the standard model. | ||
| Links: e-print arXiv:1707.02909 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; | ||
| Figures & Tables | Summary | Additional Figures & Tables | References | CMS Publications |
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| Figures | |
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Figure 1:
Feynman diagrams contributing to Higgs pair production via gluon-gluon fusion at leading order at the LHC. |
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Figure 2:
Distributions of the events observed in the signal regions of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. The first, second, and third rows show the resolved 1b1j, 2b, and boosted regions, respectively. Panels in the right column show the distribution of the ${m_\text {T2}} $ variable, while the other panels show the distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable, separated in the low-mass (LM, left panels) and high-mass (HM, central panels) regions for the resolved event categories. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-a:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 1b1j signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. The distribution is shown in the low-mass (LM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-b:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 1b1j signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. The distribution is shown in the high-mass (HM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-c:
Distribution of the ${m_\text {T2}} $ variable for events observed in the resolved 1b1j signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-d:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 2b signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. The distribution is shown in the low-mass (LM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-e:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 2b signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. The distribution is shown in the high-mass (HM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-f:
Distribution of the ${m_\text {T2}} $ variable for events observed in the resolved 2b signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-g:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the boosted signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 2-h:
Distribution of the ${m_\text {T2}} $ variable for events observed in the boosted signal region of the $ {\tau _\mu {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3:
Distributions of the events observed in the signal regions of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. The first, second, and third rows show the resolved 1b1j, 2b, and boosted regions, respectively. Panels in the right column show the distribution of the ${m_\text {T2}} $ variable, while the other panels show the distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable, separated in the low-mass (LM, left panels) and high-mass (HM, central panels) regions for the resolved event categories. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-a:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 1b1j signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. The distribution is shown in the low-mass (LM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-b:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 1b1j signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. The distribution is shown in the high-mass (HM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-c:
Distribution of the ${m_\text {T2}} $ variable for events observed in the resolved 1b1j signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-d:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 2b signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. The distribution is shown in the low-mass (LM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-e:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the resolved 2b signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. The distribution is shown in the high-mass (HM) region. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-f:
Distribution of the ${m_\text {T2}} $ variable for events observed in the resolved 2b signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-g:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable for events observed in the boosted signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 3-h:
Distribution of the ${m_\text {T2}} $ variable for events observed in the boosted signal region of the $ {\tau _{\mathrm{e}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4:
Distributions of the events observed in the signal regions of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. The first, second, and third rows show the resolved 1b1j, 2b, and boosted regions, respectively. Panels in the left column show the distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ variable and panels in the right column show the distribution of the ${m_\text {T2}}$ variable. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4-a:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ for events observed in the resolved 1b1j region of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4-b:
Distribution of the ${m_\text {T2}}$ for events observed in the resolved 1b1j region of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4-c:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ for events observed in the resolved 2b region of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4-d:
Distribution of the ${m_\text {T2}}$ for events observed in the resolved 2b region of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4-e:
Distribution of the ${m_{ {\mathrm{ H } \mathrm{ H } } }^\text {KinFit} }$ for events observed in the boosted region of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 4-f:
Distribution of the ${m_\text {T2}}$ for events observed in the boosted region of the $ { {\tau _\mathrm {h}} {\tau _\mathrm {h}} } $ final state. Data are represented by points with error bars and expected signal contributions are represented by the solid (BSM HH signals) and dashed (SM nonresonant HH signal) lines. Expected background contributions (shaded histograms) and associated systematic uncertainties (dashed areas) are shown as obtained after the maximum likelihood fit to the data under the background-only hypothesis. The background histograms are stacked while the signal histograms are not stacked. |
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Figure 5:
(upper) Observed and expected 95% CL upper limits on cross section times branching fraction as a function of the mass of the resonance $ {m_\mathrm {S} }$ under the hypothesis that its intrinsic width is negligible with respect to the experimental resolution. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The red line denotes the expectation for the production of a radion, a spin-0 state predicted in WED models, for the parameters $\Lambda _\text {R} = $ 3 TeV (mass scale) and $\text {kL} = $ 35 (size of the extra dimension), assuming the absence of mixing with the Higgs boson. (lower) Interpretation of the exclusion limit in the context of the hMSSM model, parametrized as a function of the $\tan\beta $ and $m_\mathrm {A}$ parameters. In this model, the CP-even lighter scalar is assumed to be the observed 125 GeV Higgs boson and is denoted as h, while the CP-even heavier scalar is denoted as H and the CP-odd scalar is denoted as A. The dotted lines indicate trajectories in the plane corresponding to equal values of the mass of the CP-even heavier scalar of the model, $m_\text {H}$. |
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Figure 5-a:
Observed and expected 95% CL upper limits on cross section times branching fraction as a function of the mass of the resonance $ {m_\mathrm {S} }$ under the hypothesis that its intrinsic width is negligible with respect to the experimental resolution. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The red line denotes the expectation for the production of a radion, a spin-0 state predicted in WED models, for the parameters $\Lambda _\text {R} = $ 3 TeV (mass scale) and $\text {kL} = $ 35 (size of the extra dimension), assuming the absence of mixing with the Higgs boson. |
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Figure 5-b:
Interpretation of the exclusion limit in the context of the hMSSM model, parametrized as a function of the $\tan\beta $ and $m_\mathrm {A}$ parameters. In this model, the CP-even lighter scalar is assumed to be the observed 125 GeV Higgs boson and is denoted as h, while the CP-even heavier scalar is denoted as H and the CP-odd scalar is denoted as A. The dotted lines indicate trajectories in the plane corresponding to equal values of the mass of the CP-even heavier scalar of the model, $m_\text {H}$. |
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Figure 6:
Test of $k_\lambda $ and $k_\mathrm{ t } $ anomalous couplings. The blue region denotes the parameters excluded by the data at 95% CL, while the dashed black line and the grey regions denote the expected exclusions and the 1$\sigma $ and 2$\sigma $ bands. The dotted lines indicate trajectories in the plane with equal values of cross section times branching fraction that are displayed in the associated labels. The diamond-shaped symbol denotes the couplings predicted by the SM. The theory predictions and the expected and observed limits are symmetric through a $(k_\lambda $, $k_\mathrm{ t } ) \leftrightarrow (-k_\lambda , -k_\mathrm{ t } )$ transformation. The couplings that are not explicitly tested are assumed to correspond to the SM prediction. |
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Figure 6-a:
Observed and expected 95% CL upper limits on cross section times branching fraction as a function of $k_\lambda /k_\mathrm{ t } $. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The two red bands show the theoretical cross section expectations and the corresponding uncertainties for $k_\mathrm{ t } = $ 1 and $k_\mathrm{ t } = $ 2. The couplings that are not explicitly tested are assumed to correspond to the SM prediction. |
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Figure 6-b:
Test of $k_\lambda $ and $k_\mathrm{ t } $ anomalous couplings. The blue region denotes the parameters excluded by the data at 95% CL, while the dashed black line and the grey regions denote the expected exclusions and the 1$\sigma $ and 2$\sigma $ bands. The dotted lines indicate trajectories in the plane with equal values of cross section times branching fraction that are displayed in the associated labels. The diamond-shaped symbol denotes the couplings predicted by the SM. The theory predictions and the expected and observed limits are symmetric through a $(k_\lambda $, $k_\mathrm{ t } ) \leftrightarrow (-k_\lambda , -k_\mathrm{ t } )$ transformation. The couplings that are not explicitly tested are assumed to correspond to the SM prediction. |
| Tables | |
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Table 1:
Systematic uncertainties affecting the normalization of the different processes. |
| Summary |
|
A search for resonant and nonresonant Higgs boson pair (HH) production in the $ \mathrm{ b\bar{b} } \tau\tau $ final state is presented. This search uses a data sample collected in proton-proton collisions at $ \sqrt{s} = $ 13 TeV that corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The three most sensitive decay channels of the $\tau$ lepton pair, requiring the decay of one or both $\tau$ leptons into final-state hadrons and a neutrino, are used. The results are found to be statistically compatible with the expected standard model (SM) background contribution, and upper limits at the 95% confidence level are set on the HH production cross sections. For the resonant production mechanism, upper exclusion limits at 95% confidence level (CL) are obtained for the production of a narrow resonance of mass $m_{\mathrm{X}}$ ranging from 250 to 900 GeV. These model-independent results are interpreted in the context of the hMSSM scenario, where a region in the parameter space corresponding to values of $m_\mathrm{A}$ between 230 and 360 GeV and $ \tan \beta \lesssim 2 $ is excluded at 95% CL. For the nonresonant production mechanism, the theoretical framework of an effective Lagrangian is used to parametrize the cross section as a function of anomalous couplings of the Higgs boson. Upper limits at 95% CL on the HH cross section are obtained as a function of $k_\lambda = \lambda_{\mathrm{HHH}}/\lambda_{\mathrm{HHH}}^\text{SM}$ and $k_\mathrm{ t } = y_\mathrm{ t }/y^\text{SM}_\mathrm{ t }$. The observed 95% CL upper limit corresponds to approximately 30 times the theoretical prediction for the SM cross section, and the expected limit is about 25 times the SM prediction. This is the highest sensitivity achieved so far for SM HH production at the LHC. |
| Additional Figures | |
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Additional Figure 1:
Upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \text {S})\times \mathcal {B}(\text {S}\to \mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$, shown for the three event categories. The dashed and solid lines denote respectively the observed and expected upper limits. |
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Additional Figure 1-a:
Upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \text {S})\times \mathcal {B}(\text {S}\to \mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$, shown for the three decay channels. The dashed and solid lines denote respectively the observed and expected upper limits. |
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Additional Figure 1-b:
Upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \text {S})\times \mathcal {B}(\text {S}\to \mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$, shown for the three event categories. The dashed and solid lines denote respectively the observed and expected upper limits. |
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Additional Figure 2:
Upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \mathrm{H} \mathrm{H})\times \mathcal {B}(\mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$, shown for the three decay channels (a) and the three event categories (b). The dashed and solid lines denote respectively the observed and expected upper limits. |
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Additional Figure 2-a:
Upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \mathrm{H} \mathrm{H})\times \mathcal {B}(\mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$, shown for the three decay channels. The dashed and solid lines denote respectively the observed and expected upper limits. |
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Additional Figure 2-b:
Upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \mathrm{H} \mathrm{H})\times \mathcal {B}(\mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$, shown for the three event categories. The dashed and solid lines denote respectively the observed and expected upper limits. |
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Additional Figure 3:
Observed and expected 95% CL upper limits on cross section times branching fraction for different combinations of Higgs boson couplings in the effective Lagrangian parametrization. The numbers from 1 to 12 denote the shape benchmarks defined in Ref. [1], corresponding to points in the five-dimensional parameter space with characteristic kinematic properties of the HH system. Also shown are the SM signal and the case where all couplings except $y_\text {t}$ vanish. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. |
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Additional Figure 4:
Observed and expected 95% CL upper limits on cross section times branching fraction as a function of the mass of the spin-2 resonance $m_\text {G}$ under the hypothesis that its intrinsic width is negligible with respect to the experimental resolution. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The red line denotes the expectation for the production of a graviton, a spin-2 state predicted in WED models, for the parameters $\text {kl} = $ 35 (size of the extra dimension) and $k/\overline {M}_\text {pl} = $ 0.1 (coupling to matter fields, where $\overline {M}_\text {pl} = M_\text {pl}/\sqrt {8\pi}$). The absence of mixing with the Higgs boson is assumed. |
| Additional Tables | |
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Additional Table 1:
Expected upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \text {S})\times \mathcal {B}(\text {S}\to \mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$. The limits are computed for a spin-0 resonance, and are shown separately for the three decay channels (combining the three event categories) and for the three event categories (combining the three decay channels). The combined upper limit is also shown. |
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Additional Table 2:
Observed upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \text {S})\times \mathcal {B}(\text {S}\to \mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$. The limits are computed for a spin-0 resonance, and are shown separately for the three decay channels (combining the three event categories) and for the three event categories (combining the three decay channels). The combined upper limit is also shown. |
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Additional Table 3:
Expected upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \mathrm{H} \mathrm{H})\times \mathcal {B}(\mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$. The limits are computed for different $k_\lambda /k_\text {t}$ hypotheses, and are shown separately for the three decay channels (combining the three event categories) and for the three event categories (combining the three decay channels). The combined upper limit is also shown. |
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Additional Table 4:
Observed upper limits at the 95% confidence level on $\sigma (\mathrm{g} \mathrm{g} \to \mathrm{H} \mathrm{H})\times \mathcal {B}(\mathrm{H} \mathrm{H} \to {\mathrm{b} \mathrm{b} \tau \tau})$. The limits are computed for different $k_\lambda /k_\text {t}$ hypotheses, and are shown separately for the three decay channels (combining the three event categories) and for the three event categories (combining the three decay channels). The combined upper limit is also shown. |
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