CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

CMS-HIG-24-012 ; CERN-EP-2026-157
Search for nonresonant triple Higgs boson production in the final state with six bottom quarks in proton-proton collisions at $ \sqrt{s}= $ 13 TeV
Submitted to Physical Review Letters
Abstract: A search for nonresonant triple Higgs boson ($ {\mathrm{H}\mathrm{H}\mathrm{H}} $) production in the final state with six bottom quarks is performed using proton-proton collisions at $ \sqrt{s}= $ 13 TeV corresponding to an integrated luminosity of 138 fb$ ^{-1} $ recorded by the CMS experiment. No significant excess of events over the background prediction is seen. Observed (expected) 95% confidence level upper limits on the signal cross section are set at 44 (43) fb, corresponding to 588 (572) times the standard model expectation. The observed (expected) constraint on the trilinear coupling modifier $ \kappa_3 $ is $ -7.4 < \kappa_3 < $ 12.4 ($ -6.4 < \kappa_3 < $ 11.2), assuming the quartic coupling modifier $ \kappa_4= $ 1. The corresponding constraint on $ \kappa_4 $ is $ -177 < \kappa_4 < $ 185 ($ -180 < \kappa_4 < $ 190), assuming $ \kappa_3= $ 1. This analysis provides the most stringent constraint to date on nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production and excludes, for the first time, part of the $ (\kappa_3,\kappa_4) $ space allowed by the perturbative unitarity bound.
Figures Summary Additional Figures & Tables References CMS Publications
Figures

png pdf
Figure 1:
Post-fit yields in the SR categories with three reconstructed H. Bins correspond to ten intervals per category of the SPANET score $ \mathrm{ProbMultiH} $ in the high-score range 0.8--1.0, ordered by increasing purity.

png pdf
Figure 2:
Expected and observed ULs on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength shown separately for merged, partially merged, and resolved event topologies, along with the combined result (left). The 68 and 95% CL contours in the $ (\kappa_3,\kappa_4) $ plane from the combined profile likelihood scan (right). The gray region denotes parameter space allowed by perturbative unitarity in $ \mathrm{H}\mathrm{H}\to\mathrm{H}\mathrm{H} $ scattering [47].

png pdf
Figure 2-a:
Expected and observed ULs on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength shown separately for merged, partially merged, and resolved event topologies, along with the combined result (left). The 68 and 95% CL contours in the $ (\kappa_3,\kappa_4) $ plane from the combined profile likelihood scan (right). The gray region denotes parameter space allowed by perturbative unitarity in $ \mathrm{H}\mathrm{H}\to\mathrm{H}\mathrm{H} $ scattering [47].

png pdf
Figure 2-b:
Expected and observed ULs on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength shown separately for merged, partially merged, and resolved event topologies, along with the combined result (left). The 68 and 95% CL contours in the $ (\kappa_3,\kappa_4) $ plane from the combined profile likelihood scan (right). The gray region denotes parameter space allowed by perturbative unitarity in $ \mathrm{H}\mathrm{H}\to\mathrm{H}\mathrm{H} $ scattering [47].

png pdf
Figure 3:
Representative leading-order Feynman diagrams for nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production via gluon fusion. The last three diagrams provide direct sensitivity to the trilinear ($ \lambda_3 $) and quartic ($ \lambda_4 $) H self-couplings.

png pdf
Figure 3-a:
Representative leading-order Feynman diagrams for nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production via gluon fusion. The last three diagrams provide direct sensitivity to the trilinear ($ \lambda_3 $) and quartic ($ \lambda_4 $) H self-couplings.

png pdf
Figure 3-b:
Representative leading-order Feynman diagrams for nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production via gluon fusion. The last three diagrams provide direct sensitivity to the trilinear ($ \lambda_3 $) and quartic ($ \lambda_4 $) H self-couplings.

png pdf
Figure 3-c:
Representative leading-order Feynman diagrams for nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production via gluon fusion. The last three diagrams provide direct sensitivity to the trilinear ($ \lambda_3 $) and quartic ($ \lambda_4 $) H self-couplings.

png pdf
Figure 3-d:
Representative leading-order Feynman diagrams for nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production via gluon fusion. The last three diagrams provide direct sensitivity to the trilinear ($ \lambda_3 $) and quartic ($ \lambda_4 $) H self-couplings.

png pdf
Figure 4:
Observed and expected 95% CL upper limits on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength $ \mu_{{\mathrm{H}\mathrm{H}\mathrm{H}}} $. Results are shown for the analyzed dataset of 138 fb$ ^{-1} $ of pp collisions at $ \sqrt{s}= $ 13 TeV, along with projections for 14 TeV and an integrated luminosity of 3$ \text{ab}^{-1}$.

png pdf
Figure 5:
Expected 68 and 95% CL constraints in the $ (\kappa_3,\kappa_4) $ plane for the $ \mathrm{H}\mathrm{H}\mathrm{H} \to 6\mathrm{b} $ analysis in the HL-LHC scenario ($ \sqrt{s}= $ 14 TeV, 3$ \text{ab}^{-1}$). The unitarity boundary is overlaid, and the best-fit point from the projection is indicated.
Summary
In summary, this Letter presents a search for nonresonant triple Higgs boson ($ {\mathrm{H}\mathrm{H}\mathrm{H}} $) production in the final state with six bottom quarks using 138 fb$ ^{-1} $ of proton-proton collision data at $\sqrt{s}=13$ TeV collected by the CMS experiment between 2016 and 2018. No significant deviation from the background prediction is observed. At 95% confidence level, the observed (expected) upper limit on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production cross section is 44 (43) fb, corresponding to 588 (572) times the standard model prediction. In the framework of Higgs boson self-coupling modifiers ($\kappa$), the search constrains the trilinear coupling modifier $\kappa_3$ to $-7.4 < \kappa_3 < 12.4$ for the quartic coupling modifier $\kappa_4=1$ and constrains $\kappa_4$ to $-177 < \kappa_4 < 185$ for $\kappa_3=1$. The two-dimensional $(\kappa_3,\kappa_4)$ scan constrains, for the first time in a direct search for nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production, the perturbative unitarity boundary and excludes part of the allowed parameter space. These results are the most stringent constraints to date on nonresonant $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ production and on $\kappa_4$.
Additional Figures

png pdf
Additional Figure 1:
Profile likelihood scans of the trilinear Higgs boson self-coupling modifier $\kappa_3$ ($\kappa_4=1$), shown separately for events with 2$\mathrm{H}$, 3$\mathrm{H}$, and their combination. Solid (dashed) curves correspond to the observed (expected) scan; horizontal lines indicate the $1\sigma$ and $2\sigma$ intervals.

png pdf
Additional Figure 2:
Profile likelihood scans of the quartic Higgs boson self-coupling modifier $\kappa_4$ ($\kappa_3=1$), shown separately for events with 2$\mathrm{H}$, 3$\mathrm{H}$, and their combination. Solid (dashed) curves correspond to the observed (median expected) scan; horizontal lines indicate the $1\sigma$ and $2\sigma$ intervals.

png pdf
Additional Figure 3:
Expected 68% and 95% CL constraints in the $(\kappa_3,\kappa_4)$ plane from the $ {\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $analysis under alternative treatments of the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ contribution: the nominal modeling, a model excluding the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ process, and a model including $\kappa_4$-dependent electroweak corrections in $ {\mathrm{H}\mathrm{H}\mathrm{H}} $. The unitarity boundary and best-fit point are overlaid.

png pdf
Additional Figure 4:
Observed 68% and 95% CL constraints in the $(\kappa_3,\kappa_4)$ plane from the $ {\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $analysis under alternative treatments of the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ contribution (nominal; no $ {\mathrm{H}\mathrm{H}\mathrm{H}} $; $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ with $\kappa_4$-dependent electroweak corrections). The unitarity boundary and best-fit point are shown.

png pdf
Additional Figure 5:
Expected 68% and 95% CL constraints in the $(\kappa_3,\kappa_4)$ plane for integrated luminosities of 3 and 6 ab$ ^{-1} $. The unitarity boundary and the SM point are shown.

png pdf
Additional Figure 6:
Expected and observed 95% CL upper limits on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} $ for the 2$\mathrm{H}$ region (events with two reconstructed Higgs bosons) and its subcategories. Categories are labeled by the number of merged Higgs boson candidates (mh) and resolved Higgs boson candidates (h); the median expected limit and the $\pm1\sigma$ ($\pm2\sigma$) bands are shown.

png pdf
Additional Figure 7:
Expected and observed 95% CL upper limits on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} $ for the 3$\mathrm{H}$ region (events with three reconstructed Higgs bosons) and its subcategories, labeled by the number of merged (mh) and resolved (h) Higgs boson candidates. The median expected limit and the $\pm1\sigma$ ($\pm2\sigma$) bands are shown.

png pdf
Additional Figure 8:
Expected and observed 95% CL upper limits on $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} $ for each $ {\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $analysis category (labeled by the number of merged and resolved Higgs boson candidates) and for their combination. The median expected limit and the $\pm1\sigma$ ($\pm2\sigma$) bands are shown.

png pdf
Additional Figure 9:
Summary of the expected and observed 95% CL upper limits on the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal strength $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} $ for the 2$\mathrm{H}$ and 3$\mathrm{H}$ regions and their combination. The median expected limit and the $\pm1\sigma$ ($\pm2\sigma$) bands are shown.

png pdf
Additional Figure 10:
Impact of uncertainty groupings on the expected and observed 95% CL upper limits on $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} $ in the $ {\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $analysis. Limits are recomputed under alternative configurations (nominal; removing background uncertainties; background-only; MC-only; theory-only; and statistical-only), illustrating the relative contribution of each uncertainty class.

png pdf
Additional Figure 11:
Post-fit distribution of the binned SPANET discriminant in the 0$\mathrm{H}$ (0mh0h) category of the $ {\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $analysis at 13 TeV with 138fb$ ^{-1} $ , shown on a linear scale. The fitted background components (QCD multijet and $ {\mathrm{H}\mathrm{H}\mathrm{H}} $) are stacked and compared to data; the $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal shape is overlaid for the SM expectation and scaled to the observed upper limit for visibility. The lower panel shows the data-to-prediction ratio with the post-fit uncertainty band.

png pdf
Additional Figure 12:
Post-fit distribution of the binned SPANET discriminant in the 1$\mathrm{H}$ categories (1mh0h and 0mh1h), shown on a linear scale. Vertical dashed lines separate the category-specific bin ranges; the stacked post-fit backgrounds, overlaid $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal reference, and data-to-prediction ratio are shown.

png pdf
Additional Figure 13:
Post-fit distribution of the binned SPANET discriminant in the 2$\mathrm{H}$ categories (2mh0h, 1mh1h, and 0mh2h), shown on a linear scale. Vertical dashed lines separate the category-specific bin ranges; the stacked post-fit backgrounds, overlaid $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal reference, and data-to-prediction ratio are shown.

png pdf
Additional Figure 14:
Post-fit distribution of the binned SPANET discriminant in the 3$\mathrm{H}$ categories (3mh0h, 2mh1h, 1mh2h, and 0mh3h), shown on a linear scale. Vertical dashed lines separate the category-specific bin ranges; the stacked post-fit backgrounds, overlaid $ {\mathrm{H}\mathrm{H}\mathrm{H}} $ signal reference, and data-to-prediction ratio are shown.

png pdf
Additional Figure 15:
Post-fit distribution of the binned SPANET discriminant in the 0$\mathrm{H}$ (0mh0h) category of the $ {\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $analysis at 13 TeV with 138fb$ ^{-1} $ , shown with a logarithmic $y$-axis to emphasize the low-yield and high-discriminant regions.

png pdf
Additional Figure 16:
Post-fit distribution of the binned SPANET discriminant in the 1$\mathrm{H}$ categories (1mh0h and 0mh1h), shown with a logarithmic $y$-axis to emphasize the low-yield and high-discriminant regions.

png pdf
Additional Figure 17:
Post-fit distribution of the binned SPANET discriminant in the 2$\mathrm{H}$ categories (2mh0h, 1mh1h, and 0mh2h), shown with a logarithmic $y$-axis to emphasize the low-yield and high-discriminant regions.

png pdf
Additional Figure 18:
Post-fit distribution of the binned SPANET discriminant in the 3$\mathrm{H}$ categories (3mh0h, 2mh1h, 1mh2h, and 0mh3h), shown with a logarithmic $y$-axis to emphasize the low-yield and high-discriminant regions.

png pdf
Additional Figure 19:
Selection efficiency as a function of the trilinear coupling modifier $\kappa_3$ for simulated $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $ (solid) and $$\mathrm{H}$$\mathrm{H}$ \to 4\PQb$ (dashed) samples. Efficiencies are shown after baseline preselection (black), after the $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $ like categorization in the inclusive region (green) and signal region (blue), and after the final SPANET requirement (red).

png pdf
Additional Figure 20:
Selection efficiency as a function of the quartic coupling modifier $\kappa_4$ for simulated $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $ events. Efficiencies are shown after baseline preselection (black), after the $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $ like categorization in the inclusive region (green) and signal region (blue), and after the final SPANET requirement (red).

png pdf
Additional Figure 21:
Selection efficiency versus $\kappa_3$ for $\mathrm{H}\mathrm{H}\mathrm{H}$(solid) and $\mathrm{H}\mathrm{H}$(dashed) signals at successive selections: baseline, inclusive categorization, $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $ selection, and final SPANET requirement.

png pdf
Additional Figure 22:
Selection efficiency versus $\kappa_4$ for $\mathrm{H}\mathrm{H}\mathrm{H}$(solid) and $\mathrm{H}\mathrm{H}$(dashed) signals at successive selections: baseline, inclusive categorization, $ \mu_{\mathrm{H}\mathrm{H}\mathrm{H}} \to 6\mathrm{b} $ selection, and final SPANET requirement.
Additional Tables

png pdf
Additional Table 1:
Summary of the Monte Carlo simulated processes used in the analysis, listing the event generator configuration, nominal perturbative accuracy of the generated samples, the cross-section normalization order, and the production cross section at $\sqrt{s}=13$ TeV in pb.

png pdf
Additional Table 2:
Composition of reconstructible $\mathrm{H}$ boson candidates based on MC simulation. Columns list the number of candidates reconstructed in two small-radius jets (0h, 1h, 2h, 3h) and rows list the number of candidates reconstructed in one large-radius jet (3mh, 2mh, 1mh, 0mh).

png pdf
Additional Table 3:
Benchmark cross sections for $gg \to {\mathrm{H}\mathrm{H}\mathrm{H}} $ and $gg \to {\mathrm{H}\mathrm{H}}$ as a function of $(\kappa_3,\kappa_4)$ (or $\kappa_3$ for $ {\mathrm{H}\mathrm{H}\mathrm{H}} $), including associated theoretical uncertainties. These values define the coupling-scan points used to map limits in the $(\kappa_3,\kappa_4)$ parameter space.
References
1 F. Englert and R. Brout Broken symmetry and the mass of gauge vector mesons PRL 13 (1964) 321
2 P. W. Higgs Broken symmetries, massless particles and gauge fields PL 12 (1964) 132
3 P. W. Higgs Broken symmetries and the masses of gauge bosons PRL 13 (1964) 508
4 G. S. Guralnik, C. R. Hagen, and T. W. B. Kibble Global conservation laws and massless particles PRL 13 (1964) 585
5 P. W. Higgs Spontaneous symmetry breakdown without massless bosons PR 145 (1966) 1156
6 T. W. B. Kibble Symmetry breaking in non-Abelian gauge theories PR 155 (1967) 1554
7 ATLAS Collaboration Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC PLB 716 (2012) 1 1207.7214
8 CMS Collaboration Observation of a new boson with mass near 125 GeV in pp collisions at the LHC PLB 716 (2012) 30 CMS-HIG-12-028
1207.7235
9 CMS Collaboration Observation of a new boson with mass near 125 GeV in pp collisions at $ \sqrt{s}= $ 7 and 8 TeV JHEP 06 (2013) 081 CMS-HIG-12-036
1303.4571
10 B. Horn The Higgs field and early universe cosmology: A (brief) review Physics 2 (2020) 503 2007.10377
11 M. Reichert et al. Probing baryogenesis through the Higgs boson self-coupling PRD 97 (2018) 075008 1711.00019
12 A. Noble and M. Perelstein Higgs self-coupling as a probe of the electroweak phase transition PRD 78 (2008) 063518 0711.3018
13 T. Markkanen, A. Rajantie, and S. Stopyra Cosmological Aspects of Higgs Vacuum Metastability Front. Astron. Space Sci. 5 (2018) 40 1809.06923
14 M. Grazzini et al. Higgs boson pair production at NNLO with top quark mass effects JHEP 05 (2018) 059 1803.02463
15 S. Dawson, S. Dittmaier, and M. Spira Neutral Higgs-boson pair production at hadron colliders: QCD corrections PRD 58 (1998) 115012 hep-ph/9805244
16 S. Borowka et al. Higgs boson pair production in gluon fusion at next-to-leading order with full top-quark mass dependence [Erratum: \doi10.1103/PhysRevLett.117.079901], 2016
PRL 117 (2016) 012001
1604.06447
17 J. Baglio et al. Gluon fusion into Higgs pairs at NLO QCD and the top mass scheme EPJC 79 (2019) 459 1811.05692
18 D. de Florian and J. Mazzitelli Higgs boson pair production at next-to-next-to-leading order in QCD PRL 111 (2013) 201801 1309.6594
19 D. Y. Shao, C. S. Li, H. T. Li, and J. Wang Threshold resummation effects in Higgs boson pair production at the LHC JHEP 07 (2013) 169 1301.1245
20 D. de Florian and J. Mazzitelli Higgs pair production at next-to-next-to-leading logarithmic accuracy at the LHC JHEP 09 (2015) 053 1505.07122
21 J. Baglio et al. $ \mathrm{g}\mathrm{g}\to\mathrm{H}\mathrm{H} $: Combined uncertainties PRD 103 (2021) 056002 2008.11626
22 G. Heinrich, J. Lang, and L. Scyboz SMEFT predictions for $ \mathrm{g}\mathrm{g} \to \mathrm{H}\mathrm{H} $ at full NLO QCD and truncation uncertainties JHEP 08 (2022) 079 2204.13045
23 E. Bagnaschi, G. Degrassi, and R. Gröber Higgs boson pair production at NLO in the POWHEG approach and the top quark mass uncertainties EPJC 83 (2023) 1054 2309.10525
24 F. Maltoni, E. Vryonidou, and M. Zaro Top-quark mass effects in double and triple Higgs production in gluon-gluon fusion at NLO JHEP 11 (2014) 079 1408.6542
25 A. Papaefstathiou and G. Tetlalmatzi-Xolocotzi Multi-Higgs boson production with anomalous interactions at current and future proton colliders JHEP 06 (2024) 124 2312.13562
26 D. de Florian, I. Fabre, and J. Mazzitelli Triple Higgs production at hadron colliders at NNLO in QCD JHEP 03 (2020) 155 1912.02760
27 H. Abouabid et al. HHH whitepaper EPJC 84 (2024) 1183 2407.03015
28 LHC Higgs Cross Section Working Group Handbook of LHC Higgs Cross Sections: 3. Higgs properties CERN Yellow Rep. Monogr, 2013
link
1307.1347
29 ATLAS Collaboration Studies of new Higgs boson interactions through nonresonant HH production in the $ \mathrm{b}\overline{\mathrm{b}}\gamma\gamma $ final state in pp collisions at $ \sqrt{s} = $ 13 TeV with the ATLAS detector JHEP 01 (2024) 066 2310.12301
30 ATLAS Collaboration Search for nonresonant pair production of Higgs bosons in the $ \mathrm{b}\overline{\mathrm{b}}\mathrm{b}\overline{\mathrm{b}} $ final state in pp collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector PRD 108 (2023) 052003 2301.03212
31 ATLAS Collaboration Search for the nonresonant production of Higgs boson pairs via gluon fusion and vector-boson fusion in the $ \mathrm{b}\overline{\mathrm{b}}\tau^{+}\tau^{-} $ final state in proton-proton collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector PRD 110 (2024) 032012 2404.12660
32 ATLAS Collaboration Search for non-resonant Higgs boson pair production in final states with leptons, taus, and photons in pp collisions at $ \sqrt{s} = $ 13 TeV with the ATLAS detector JHEP 08 (2024) 164 2405.20040
33 ATLAS Collaboration Search for non-resonant Higgs boson pair production in the 2 $ \mathrm{b}+2\ell+E_{\mathrm{T}}^{\text{miss}} $ final state in pp collisions at $ \sqrt{s} = $ 13 TeV with the ATLAS detector JHEP 02 (2024) 037 2310.11286
34 CMS Collaboration Search for nonresonant Higgs boson pair production in final state with two bottom quarks and two tau leptons in proton-proton collisions at $ \sqrt{s} = $ 13 TeV PLB 842 (2023) 137531 CMS-HIG-20-010
2206.09401
35 CMS Collaboration Search for Higgs boson pair production with one associated vector boson in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JHEP 10 (2024) 061 CMS-HIG-22-006
2404.08462
36 CMS Collaboration Search for Higgs boson pairs decaying to WW*WW*, WW*$ \tau\tau $, and $ \tau\tau\tau\tau $ in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JHEP 07 (2023) 095 CMS-HIG-21-002
2206.10268
37 CMS Collaboration Search for Higgs boson pair production in the $ \textrm{b}\overline{\textrm{b}}{\textrm{W}}^{+}{\textrm{W}}^{-} $ decay mode in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JHEP 07 (2024) 293 CMS-HIG-21-005
2403.09430
38 ATLAS Collaboration Combination of searches for Higgs boson pair production in pp collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector PRL 133 (2024) 101801 2406.09971
39 CMS Collaboration A portrait of the Higgs boson by the CMS experiment ten years after the discovery [Corrigendum: \DOI10./s41586-023-06164-8], 2022
Nature 607 (2022) 60
CMS-HIG-22-001
2207.00043
40 ATLAS Collaboration Search for pair production of boosted Higgs bosons via vector-boson fusion in the $ \mathrm{b}\overline{\mathrm{b}}\mathrm{b}\overline{\mathrm{b}} $ final state using pp collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector PLB 858 (2024) 139007 2404.17193
41 CMS Collaboration Search for Higgs boson pair production in the four b quark final state in proton-proton collisions at $ \sqrt{s}= $ 13 TeV PRL 129 (2022) 081802 CMS-HIG-20-005
2202.09617
42 CMS Collaboration Search for nonresonant pair production of highly energetic Higgs bosons decaying to bottom quarks PRL 131 (2023) 041803 2205.06667
43 ATLAS Collaboration Search for triple Higgs boson production in the 6 b final state using pp collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector PRD 111 (2025) 032006 2411.02040
44 W. Bizo \'n , U. Haisch, and L. Rottoli Constraints on the quartic Higgs self-coupling from double-Higgs production at future hadron colliders JHEP 10 (2019) 267 1810.04665
45 W. Bizo \'n et al. Addendum to: Constraints on the quartic Higgs self-coupling from double-Higgs production at future hadron colliders JHEP 02 (2024) 170 2402.03463
46 CMS Collaboration Combination of searches for nonresonant Higgs boson pair production in proton-proton collisions at $ \sqrt{s}= $ 13 TeV Submitted to J. Phys. G, 2025 CMS-HIG-20-011
2510.07527
47 P. Stylianou and G. Weiglein Constraints on the trilinear and quartic Higgs couplings from triple Higgs production at the LHC and beyond EPJC 84 (2024) 366 2312.04646
48 L. Biermann et al. Double and triple Higgs boson production to probe the electroweak phase transition PRD 110 (2024) 095012 2408.08043
49 D. Egana-Ugrinovic, S. Homiller, and P. Meade Aligned and spontaneous flavor violation PRL 123 (2019) 031802 1811.00017
50 D. Egana-Ugrinovic, S. Homiller, and P. R. Meade Higgs bosons with large couplings to light quarks PRD 100 (2019) 115041 1908.11376
51 B. Fuks, J. H. Kim, and S. J. Lee Probing Higgs self-interactions in proton-proton collisions at a center-of-mass energy of 100 TeV PRD 93 (2016) 035026 1510.07697
52 A. Papaefstathiou, G. Tetlalmatzi-Xolocotzi, and M. Zaro Triple Higgs boson production to six b-jets at a 100 TeV proton collider EPJC 79 (2019) 947 1909.09166
53 CMS Collaboration Precision luminosity measurement in proton-proton collisions at $ \sqrt{s}= $ 13 TeV in 2015 and 2016 at CMS EPJC 81 (2021) 800 CMS-LUM-17-003
2104.01927
54 CMS Collaboration CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2018
link
CMS-PAS-LUM-17-004
55 CMS Collaboration CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2019
link
CMS-PAS-LUM-18-002
56 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004
57 CMS Collaboration Development of the CMS detector for the CERN LHC Run 3 JINST 19 (2024) P05064 CMS-PRF-21-001
2309.05466
58 CMS Collaboration Performance of the CMS Level-1 trigger in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JINST 15 (2020) P10017 CMS-TRG-17-001
2006.10165
59 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
60 CMS Collaboration Performance of the CMS high-level trigger during LHC run 2 JINST 19 (2024) P11021 CMS-TRG-19-001
2410.17038
61 CMS Collaboration Electron and photon reconstruction and identification with the CMS experiment at the CERN LHC JINST 16 (2021) P05014 CMS-EGM-17-001
2012.06888
62 CMS Collaboration Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $ \sqrt{s}= $ 13 TeV JINST 13 (2018) P06015 CMS-MUO-16-001
1804.04528
63 CMS Collaboration Description and performance of track and primary-vertex reconstruction with the CMS tracker JINST 9 (2014) P10009 CMS-TRK-11-001
1405.6569
64 J. Alwall et al. The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations JHEP 07 (2014) 079 1405.0301
65 P. Nason A new method for combining NLO QCD with shower Monte Carlo algorithms JHEP 11 (2004) 040 hep-ph/0409146
66 S. Frixione, P. Nason, and C. Oleari Matching NLO QCD computations with parton shower simulations: the POWHEG method JHEP 11 (2007) 070 0709.2092
67 S. Alioli, P. Nason, C. Oleari, and E. Re A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG box JHEP 06 (2010) 043 1002.2581
68 E. Bagnaschi, G. Degrassi, P. Slavich, and A. Vicini Higgs production via gluon fusion in the POWHEG approach in the SM and in the MSSM JHEP 02 (2012) 088 1111.2854
69 G. Heinrich et al. NLO predictions for Higgs boson pair production with full top quark mass dependence matched to parton showers JHEP 08 (2017) 088 1703.09252
70 S. Jones and S. Kuttimalai Parton shower and NLO-matching uncertainties in Higgs boson pair production JHEP 02 (2018) 176 1711.03319
71 G. Buchalla et al. Higgs boson pair production in non-linear effective field theory with full $ m_\mathrm{t} $-dependence at NLO QCD JHEP 09 (2018) 057 1806.05162
72 G. Heinrich et al. Probing the trilinear Higgs boson coupling in di-Higgs production at NLO QCD including parton shower effects JHEP 06 (2019) 066 1903.08137
73 G. Heinrich, S. P. Jones, M. Kerner, and L. Scyboz A non-linear EFT description of $ \mathrm{g}\mathrm{g}\to\mathrm{H}\mathrm{H} $ at NLO interfaced to POWHEG JHEP 10 (2020) 021 2006.16877
74 J. Davies et al. Double Higgs boson production at NLO: Combining the exact numerical result and high-energy expansion JHEP 11 (2019) 024 1907.06408
75 T. Sjöstrand et al. An introduction to PYTHIA 8.2 Comput. Phys. Commun. 191 (2015) 159 1410.3012
76 CMS Collaboration Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements EPJC 80 (2020) 4 CMS-GEN-17-001
1903.12179
77 NNPDF Collaboration Parton distributions from high-precision collider data EPJC 77 (2017) 663 1706.00428
78 CMS Collaboration Particle-flow reconstruction and global event description with the CMS detector JINST 12 (2017) P10003 CMS-PRF-14-001
1706.04965
79 CMS Collaboration Pileup removal algorithms CMS Physics Analysis Summary, 2014
CMS-PAS-JME-14-001
CMS-PAS-JME-14-001
80 D. Bertolini, P. Harris, M. Low, and N. Tran Pileup per particle identification JHEP 10 (2014) 059 1407.6013
81 CMS Collaboration Pileup mitigation at CMS in 13 TeV data JINST 15 (2020) P09018 CMS-JME-18-001
2003.00503
82 M. Cacciari, G. P. Salam, and G. Soyez The anti-$ k_{\mathrm{T}} $ jet clustering algorithm JHEP 04 (2008) 063 0802.1189
83 M. Cacciari, G. P. Salam, and G. Soyez FastJet user manual EPJC 72 (2012) 1896 1111.6097
84 H. Qu and L. Gouskos Jet tagging via particle clouds PRD 101 (2020) 056019 1902.08570
85 CMS Collaboration Performance of the PARTICLENET} \MATHRM{B and $ \mathrm{b}\mathrm{b} $-tagging algorithms in the CMS High-Level Trigger in Run 3 CMS Detector Performance Note CMS-DP-2025-009, 2025
CDS
86 CMS Collaboration Simultaneous probe of the charm and bottom quark Yukawa couplings using $ {\mathrm{t}\overline{\mathrm{t}}} \mathrm{H} $ events PRL 136 (2026) 011801 CMS-HIG-24-018
2509.22535
87 CMS Collaboration Search for $ \gamma\mathrm{H} $ production and constraints on the Yukawa couplings of light quarks to the Higgs boson PRD 112 (2025) 112001 CMS-HIG-23-011
2502.05665
88 CMS Collaboration HEPData record for this analysis link
89 A. Shmakov et al. SPANET: Generalized permutationless set assignment for particle physics using symmetry preserving attention SciPost Phys. 12 (2022) 178 2106.03898
90 M. J. Fenton et al. Permutationless many-jet event reconstruction with symmetry preserving attention networks PRD 105 (2022) 112008 2010.09206
91 M. J. Fenton et al. Reconstruction of unstable heavy particles using deep symmetry-preserving attention networks Comm. Phys. 7 (2024) 139 2309.01886
92 C.-W. Chiang, F.-Y. Hsieh, S.-C. Hsu, and I. Low Deep learning to improve the sensitivity of di-Higgs searches in the 4b channel JHEP 09 (2024) 139 2401.14198
93 H. Li et al. Reconstruction of boosted and resolved multi-Higgs-boson events with symmetry-preserving attention networks JHEP 11 (2025) 119 2412.03819
94 R. E. Schapire, The Boosting Approach to Machine Learning: An Overview link
95 R. Frederix et al. Higgs pair production at the LHC with NLO QCD corrections and parton-shower effects PLB 732 (2014) 142 1401.7340
96 F. Maltoni, D. Pagani, A. Shivaji, and X. Zhao Trilinear Higgs coupling determination via single-Higgs differential measurements at the LHC EPJC 77 (2017) 887 1709.08649
97 U. Haisch, A. Sankar, and G. Zanderighi A new probe of the quartic Higgs self-coupling PRL 136 (2026) 011801 2505.20463
98 ATLAS and CMS Collaborations, and LHC Higgs Combination Group Procedure for the LHC Higgs boson search combination in Summer 2011 Technical Report CMS-NOTE-2011-005, ATL-PHYS-PUB-2011-11, 2011
99 G. Cowan, K. Cranmer, E. Gross, and O. Vitells Asymptotic formulae for likelihood-based tests of new physics EPJC 71 (2011) 1554 1007.1727
100 T. Junk Confidence level computation for combining searches with small statistics NIM A 434 (1999) 435 hep-ex/9902006
101 A. L. Read Presentation of search results: the $ \mathit{CL}_{s} $ technique JPG 28 (2002) 2693
102 CMS Collaboration The CMS statistical analysis and combination tool: Combine Comput. Softw. Big Sci. 8 (2024) 19 CMS-CAT-23-001
2404.06614
103 W. Verkerke and D. Kirkby The RooFit toolkit for data modeling in the International Conference on Computing in High Energy and Nuclear Physics (CHEP ): La Jolla CA, United States, March 24--28, 2003
Proc. 1 (2003) 3
physics/0306116
104 L. Moneta et al. The RooStats project in the International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT ): Jaipur, India, February 22--27, 2010
Proc. 1 (2010) 3
1009.1003
105 J.-L. Ding et al. Constraining the Higgs potential using multi-Higgs production SciPost Phys. Comm. Rep. 2 (2026) 4 2601.13248
106 A. Carvalho et al. Higgs pair production: Choosing benchmarks with cluster analysis JHEP 04 (2016) 126 1507.02245
107 M. Capozi and G. Heinrich Exploring anomalous couplings in Higgs boson pair production through shape analysis JHEP 03 (2020) 091 1908.08923
108 J. Baglio et al. The measurement of the Higgs self-coupling at the LHC: Theoretical status JHEP 04 (2013) 151 1212.5581
109 S. Frixione, P. Nason, and G. Ridolfi A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction JHEP 09 (2007) 126 0707.3088
110 T. Je \v z o et al. An NLO+PS generator for $ {\mathrm{t}\overline{\mathrm{t}}} $ and $ \mathrm{W}\mathrm{t} $ production and decay including non-resonant and interference effects EPJC 76 (2016) 691 1607.04538
111 M. Czakon and A. Mitov Top++: A program for the calculation of the top-pair cross-section at hadron colliders Comput. Phys. Commun. 185 (2014) 2930 1112.5675
112 M. Czakon et al. Top-pair production at the LHC through NNLO QCD and NLO EW JHEP 10 (2017) 186 1705.04105
113 GEANT4 Collaboration GEANT 4---a simulation toolkit NIM A 506 (2003) 250
114 CMS Collaboration Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV JINST 12 (2017) P02014 CMS-JME-13-004
1607.03663
115 CMS Collaboration Performance of missing transverse momentum reconstruction in proton-proton collisions at $ \sqrt{s} = $ 13 TeV using the CMS detector JINST 14 (2019) P07004 CMS-JME-17-001
1903.06078
116 CMS Collaboration Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at $ \sqrt{s} = $ 8 TeV JINST 10 (2015) P06005 CMS-EGM-13-001
1502.02701
117 CMS Collaboration Search for supersymmetry in pp collisions at $ \sqrt{s}= $ 13 TeV in the single-lepton final state using the sum of masses of large-radius jets JHEP 08 (2016) 122 CMS-SUS-15-007
1605.04608
118 CMS Collaboration Projection of CMS experimental reach on HH production at HL-LHC CMS Note CMS-NOTE-2025-006, 2025
CDS
119 ATLAS and CMS Collaborations Highlights of the HL-LHC physics projections by ATLAS and CMS Submitted to
European Strategy for Particle Physics Update 202 (2025) 6
2504.00672
Compact Muon Solenoid
LHC, CERN