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| CMS-PAS-SUS-24-002 | ||
| Search for light pseudoscalar bosons produced in Higgs boson decays in the 4$ \tau $ and 2$ \mu $ 2$ \tau $ final states in proton-proton collisions at $ \sqrt{s}= $ 13 TeV | ||
| CMS Collaboration | ||
| 27 September 2024 | ||
| Abstract: A search for a pair of light pseudoscalar bosons ($ \mathrm{a}_1 $) produced from the decay of the 125 GeV Higgs boson (H) is presented. The analysis examines decay modes where one $ \mathrm{a}_1 $ decays into a pair of tau leptons, and the other decays into either another pair of tau leptons or a pair of muons. The $ \mathrm{a}_1 $ mass probed in this study ranges from 4 to 15 GeV. The data sample used was recorded by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV and corresponds to an integrated luminosity of 138 fb$ ^{-1} $. The study uses the 2$ \mu$2$\tau $ and 4$ \tau $ channels in combination to constrain the product of the Higgs boson production cross section and the branching fraction to the 4$ \tau $ final state, $ \sigma (\mathrm{pp}\to \text{H}+\text{X} ) \mathcal{B}(\text{H}\to\text{a}_{1}\text{a}_{1})\mathcal{B}^2(\text{a}_{1}\to\tau\tau) $. This methodology takes advantage of the linear dependence of the fermionic coupling strength of pseudoscalar bosons on the fermion mass. Model-independent upper limits at 95% confidence level (CL) on $ \sigma (\mathrm{pp}\to \text{H}+\text{X}) \mathcal{B}(\text{H}\to\text{a}_{1}\text{a}_{1})\mathcal{B}^2(\text{a}_{1}\to\tau\tau) $, relative to the standard model Higgs boson production cross section $ \sigma_{\text{SM}} $, are set. The observed (expected) upper limits range between 0.007 (0.011) and 0.079 (0.066) across the mass range considered. Exclusion limits at 95% on $ \sigma (\mathrm{pp}\to \text{H}+\text{X}) \mathcal{B}(\text{H}\to\text{a}_{1}\text{a}_{1}) $, relative to $ \sigma_{\text{SM}} $, are derived for various Two Higgs Doublet Model + Singlet scenarios. | ||
| Links: CDS record (PDF) ; CADI line (restricted) ; | ||
| Figures | |
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Figure 1:
Illustration of the signal topology, in which the H boson decays into two $ \mathrm{a}_1 $ bosons, where one $ \mathrm{a}_1 $ boson decays into a pair of tau leptons, while the other decays into a pair of muons or a pair of tau leptons. The analyzed final state consists of one muon and an oppositely charged track in each $ \mathrm{a}_1 $ decay. |
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Figure 2:
Binning of the 2D ($ m_1,m_2 $) distribution. |
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Figure 3:
The observed invariant mass distribution, normalized to unity, of the first muon and the softest (left) or hardest (right) accompanying ``signal'' track for different isolation requirements imposed on the second muon: one ``isolation'' track ($ N_\text{iso,2}= $ 1; circles) or two to three ``isolation'' tracks ($ N_\text{iso,2} = 2, $ 3). |
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Figure 3-a:
The observed invariant mass distribution, normalized to unity, of the first muon and the softest (left) or hardest (right) accompanying ``signal'' track for different isolation requirements imposed on the second muon: one ``isolation'' track ($ N_\text{iso,2}= $ 1; circles) or two to three ``isolation'' tracks ($ N_\text{iso,2} = 2, $ 3). |
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Figure 3-b:
The observed invariant mass distribution, normalized to unity, of the first muon and the softest (left) or hardest (right) accompanying ``signal'' track for different isolation requirements imposed on the second muon: one ``isolation'' track ($ N_\text{iso,2}= $ 1; circles) or two to three ``isolation'' tracks ($ N_\text{iso,2} = 2, $ 3). |
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Figure 4:
Normalized invariant mass distribution of the muon-track system for events passing the signal selection. Observed events are shown as black points with error bars. The background model in blue is derived from the $ N_{23} $ control region. Also shown are normalized distributions from signal simulations for four mass hypotheses, $ m_{\mathrm{a}_1} $= 5, 8, 12, and 15 GeV (dashed histograms). Signal distributions include both the 2$ \mu$2$\tau $ and 4$ \tau $ contributions. Each event contributes two entries, corresponding to the two muon-track systems in each event that pass the selection. The lower panel shows the ratio of observed to expected background events in each bin. The grey shaded area represents the uncertainty of the background model. |
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Figure 5:
The correlation factors $ C(i,j)^{\text{CR}}_{\text{data}} $ with statistical uncertainties. |
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Figure 6:
The correlation factors $ C(i,j)^{\text{SR}}_{\text{MC}} $ (upper) and $ C(i,j)^{\text{CR}}_{\text{MC}} $ (lower) with statistical uncertainties. |
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Figure 6-a:
The correlation factors $ C(i,j)^{\text{SR}}_{\text{MC}} $ (upper) and $ C(i,j)^{\text{CR}}_{\text{MC}} $ (lower) with statistical uncertainties. |
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Figure 6-b:
The correlation factors $ C(i,j)^{\text{SR}}_{\text{MC}} $ (upper) and $ C(i,j)^{\text{CR}}_{\text{MC}} $ (lower) with statistical uncertainties. |
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Figure 7:
The signal $ f_\text{2D}(i,j) $ templates for mass hypothesis $ m_{\mathrm{a}_1}= $ 5 GeV (upper left), 8 GeV (upper right), 12 GeV (lower left) and 15 GeV (lower right). The $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 2\mu 2\tau $ (blue histogram) and $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 4\tau $ (red histogram) contributions are shown. The distributions are normalized assuming SM H production cross section and $ {\mathcal{B}} (\mathrm{H}\to\mathrm{a}_1\mathrm{a}_1){\mathcal{B}}^{2}(\mathrm{a}_1\to \tau\tau) $ = 0.05. The bin notation follows that of Fig. 2. |
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Figure 7-a:
The signal $ f_\text{2D}(i,j) $ templates for mass hypothesis $ m_{\mathrm{a}_1}= $ 5 GeV (upper left), 8 GeV (upper right), 12 GeV (lower left) and 15 GeV (lower right). The $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 2\mu 2\tau $ (blue histogram) and $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 4\tau $ (red histogram) contributions are shown. The distributions are normalized assuming SM H production cross section and $ {\mathcal{B}} (\mathrm{H}\to\mathrm{a}_1\mathrm{a}_1){\mathcal{B}}^{2}(\mathrm{a}_1\to \tau\tau) $ = 0.05. The bin notation follows that of Fig. 2. |
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Figure 7-b:
The signal $ f_\text{2D}(i,j) $ templates for mass hypothesis $ m_{\mathrm{a}_1}= $ 5 GeV (upper left), 8 GeV (upper right), 12 GeV (lower left) and 15 GeV (lower right). The $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 2\mu 2\tau $ (blue histogram) and $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 4\tau $ (red histogram) contributions are shown. The distributions are normalized assuming SM H production cross section and $ {\mathcal{B}} (\mathrm{H}\to\mathrm{a}_1\mathrm{a}_1){\mathcal{B}}^{2}(\mathrm{a}_1\to \tau\tau) $ = 0.05. The bin notation follows that of Fig. 2. |
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Figure 7-c:
The signal $ f_\text{2D}(i,j) $ templates for mass hypothesis $ m_{\mathrm{a}_1}= $ 5 GeV (upper left), 8 GeV (upper right), 12 GeV (lower left) and 15 GeV (lower right). The $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 2\mu 2\tau $ (blue histogram) and $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 4\tau $ (red histogram) contributions are shown. The distributions are normalized assuming SM H production cross section and $ {\mathcal{B}} (\mathrm{H}\to\mathrm{a}_1\mathrm{a}_1){\mathcal{B}}^{2}(\mathrm{a}_1\to \tau\tau) $ = 0.05. The bin notation follows that of Fig. 2. |
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Figure 7-d:
The signal $ f_\text{2D}(i,j) $ templates for mass hypothesis $ m_{\mathrm{a}_1}= $ 5 GeV (upper left), 8 GeV (upper right), 12 GeV (lower left) and 15 GeV (lower right). The $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 2\mu 2\tau $ (blue histogram) and $ \mathrm{H}\to\mathrm{a}_1\mathrm{a}_1\to 4\tau $ (red histogram) contributions are shown. The distributions are normalized assuming SM H production cross section and $ {\mathcal{B}} (\mathrm{H}\to\mathrm{a}_1\mathrm{a}_1){\mathcal{B}}^{2}(\mathrm{a}_1\to \tau\tau) $ = 0.05. The bin notation follows that of Fig. 2. |
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Figure 8:
The ($ m_1,m_2 $) in one-row distribution used to extract the signal. The observed number of events is represented by data points with error bars. The background with its uncertainty is shown as the blue histogram with the shaded error band. The normalization for the background is obtained by fitting the observed data under the background-only hypothesis. Signal expectations for the 4$ \tau $ and 2$ \mu$2$\tau $ final states are shown as dashed histograms for the mass hypotheses $ m_{\mathrm{a}_1} $= 5, 8, 12, and 15 GeV. The relative normalization of the 4$ \tau $ and 2$ \mu$2$\tau $ final states are given by Eq. (1) as explained in Section 7. The signal normalization is computed assuming that the H boson is produced in pp collisions with a rate predicted by the SM and decays into $ \mathrm{a}_1 \mathrm{a}_1 \to 4\tau $ final state with the branching fraction of 5%. The lower plot shows the ratio of the observed data events to the expected background yield in each bin of the ($ m_1,m_2 $) distribution. |
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Figure 9:
The observed and expected upper limits at 95% confidence level on the product of the signal cross section and the branching fraction $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) {\mathcal{B}}^{2} (\mathrm{a}_1 \to \tau \tau) $, relative to the inclusive Higgs boson production cross section $ \sigma_\text{SM} $ predicted in the SM. The green and yellow bands indicate the regions containing 68% and 95% of the distribution of limits expected under the background-only hypothesis. |
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Figure 10:
The observed and expected upper limits at 95% CLs on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ m_{\mathrm{a}_1} $ for different 2HDM+S models for benchmark $ \tan\beta $ values: Type I ($ \tan\beta $ independent; upper left), Type II ($ \tan\beta = $ 5; upper right), Type III ($ \tan\beta = $ 2; lower left) and Type IV ($ \tan\beta = $ 0.5; lower right). |
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Figure 10-a:
The observed and expected upper limits at 95% CLs on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ m_{\mathrm{a}_1} $ for different 2HDM+S models for benchmark $ \tan\beta $ values: Type I ($ \tan\beta $ independent; upper left), Type II ($ \tan\beta = $ 5; upper right), Type III ($ \tan\beta = $ 2; lower left) and Type IV ($ \tan\beta = $ 0.5; lower right). |
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Figure 10-b:
The observed and expected upper limits at 95% CLs on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ m_{\mathrm{a}_1} $ for different 2HDM+S models for benchmark $ \tan\beta $ values: Type I ($ \tan\beta $ independent; upper left), Type II ($ \tan\beta = $ 5; upper right), Type III ($ \tan\beta = $ 2; lower left) and Type IV ($ \tan\beta = $ 0.5; lower right). |
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Figure 10-c:
The observed and expected upper limits at 95% CLs on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ m_{\mathrm{a}_1} $ for different 2HDM+S models for benchmark $ \tan\beta $ values: Type I ($ \tan\beta $ independent; upper left), Type II ($ \tan\beta = $ 5; upper right), Type III ($ \tan\beta = $ 2; lower left) and Type IV ($ \tan\beta = $ 0.5; lower right). |
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Figure 10-d:
The observed and expected upper limits at 95% CLs on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ m_{\mathrm{a}_1} $ for different 2HDM+S models for benchmark $ \tan\beta $ values: Type I ($ \tan\beta $ independent; upper left), Type II ($ \tan\beta = $ 5; upper right), Type III ($ \tan\beta = $ 2; lower left) and Type IV ($ \tan\beta = $ 0.5; lower right). |
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Figure 11:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type II 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 11-a:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type II 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 11-b:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type II 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 11-c:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type II 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 11-d:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type II 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 12:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type III 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 12-a:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type III 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 12-b:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type III 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 12-c:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type III 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
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Figure 12-d:
The observed and expected 95% CL upper limits on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $, as a function of $ \tan\beta $ for the Type III 2HDM+S model for: $ m_{\mathrm{a}_1} $= 5 GeV (upper left), $ m_{\mathrm{a}_1} $= 8 GeV (upper right), $ m_{\mathrm{a}_1} $= 12 GeV (lower left) and $ m_{\mathrm{a}_1} $= 15 GeV (lower right). |
| Tables | |
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Table 1:
Types of tracks considered in the analysis, with their selection criteria and purposes. |
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Table 2:
The signal acceptance and the number of expected signal events after selection in the SR. The acceptance is calculated relative to the total H production cross section, using values predicted by the SM. The number of expected signal events is computed for a benchmark value of the branching fraction $ {\mathcal{B}}(\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) {\mathcal{B}}^{2} (\mathrm{a}_1 \to \tau \tau)= $ 0.05, assuming SM-predicted cross sections. The quoted uncertainties for the predictions from simulation include only statistical uncertainties. |
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Table 3:
Control regions used to construct and validate the background model. The symbols $ N_\text{iso} $ and $ N_\text{sig} $ denote the number of ``isolation'' and ``signal'', respectively, within a cone of $ \Delta R= $ 0.5 around the muon momentum direction. In cases where $ N_\text{sig} $ is not mentioned, there is no explicit requirement on the number of ``signal'' tracks. The last row defines the SR. |
| Summary |
| A search for light pseudoscalar bosons ($ \mathrm{a}_1 $) produced in decays of the 125 GeV Higgs boson (H) in final states with four taus or two muons and two taus is presented. The search is performed using data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment at the LHC between 2016 and 2018 and corresponding to an integrated luminosity of 138 fb$ ^{-1} $. Pseudoscalar bosons with masses ($ m_{\mathrm{a}_1} $) in the range of 4 to 15 GeV are examined. The analysis is based on inclusive H boson production and targets the $ \mathrm{H}\to \mathrm{a}_1 \mathrm{a}_1 \to 4\tau/2\mu 2\tau $ decay channels. Both channels are used in combination to constrain the product of the inclusive signal production cross section and the branching fraction into the 4$ \tau $ final state, $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) \mathcal{B}^2(\mathrm{a}_1 \to \tau\tau) $. This is done by exploiting the linear dependence of the fermionic coupling strength of $ \mathrm{a}_1 $ on the fermion mass. No significant excess in data over the expected standard model (SM) background is observed. Hence, upper limits on the product of the inclusive signal cross section and the branching fraction, $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) \mathcal{B}^2(\mathrm{a}_1 \to \tau\tau) $, relative to the SM H production cross section, $ \sigma_\text{SM} $, are set at 95% confidence level. The observed limits range from 0.007 at $ m_{\mathrm{a}_1}= $ 11 GeV to 0.079 at $ m_{\mathrm{a}_1}= $ 4 GeV. The expected limits range from 0.011 at $ m_{\mathrm{a}_1}= $ 11 GeV to 0.066 at $ m_{\mathrm{a}_1}= $ 4 GeV. The results indicate significant improvement compared to the earlier similar CMS analysis at 13 TeV, exceeding the anticipated improvement resulting from the larger data sample alone. Sensitivity is enhanced by 2 to 4 times depending on the mass hypothesis, which can be attributed to the introduction of a veto for b tagged jets and the tightening of the impact parameters of the ``isolation`` tracks, both of which play a crucial role in background reduction. The results are also reinterpreted in the context of various types of 2HDM+S models. The tightest constraints on $ \sigma (\mathrm{p}\mathrm{p} \to \mathrm{H}+\text{X}) {\mathcal{B}} (\mathrm{H} \to \mathrm{a}_1 \mathrm{a}_1) $, relative to $ \sigma_\text{SM} $ are provided for Type III 2HDM+S. For this scenario, regions of the phase space with $ \tan\beta \geq $ 2 are excluded for most $ m_{\mathrm{a}_1} $. For the Type II 2HDM+S model, stringent limits are observed for mass values between 4 and 9 GeV when $ \tan\beta > $ 1, indicating strong exclusion capabilities within this mass range. \pagebreak |
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