CMS-PAS-FTR-18-020 | ||
Constraints on the Higgs boson self-coupling from ttH+tH, $\mathrm{H}\rightarrow\gamma\gamma$ differential measurements at the HL-LHC | ||
CMS Collaboration | ||
November 2018 | ||
Abstract: This note details a study of prospects for ttH+tH, $\mathrm{H}\rightarrow\gamma\gamma$ differential cross section measurements at the HL-LHC with the CMS Phase-2 detector. The study is performed using simulated proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=$ 14 TeV, corresponding to 3 ab$^{-1}$ of data. The expected performance of the upgraded CMS detector is used to model the object reconstruction efficiencies under HL-LHC conditions. The results are interpreted in terms of the expected sensitivity to deviations of the Higgs boson self-coupling, $\kappa_\lambda$, from beyond standard model effects. Using the HL-LHC data, the precision expected in ttH+tH, $\mathrm{H}\rightarrow\gamma\gamma$ differential cross section measurements will constrain $\kappa_\lambda$ within the range $-4.1 < \kappa_\lambda < 14.1$, at the 95% confidence level, assuming all other Higgs boson couplings are fixed to standard model predictions. Moreover, it is possible to disentangle the effects of a modified Higgs boson self coupling from the presence of other anomalous couplings by using the differences in the shape of the measured spectrum. This separation is unique to differential cross section measurements. The ultimate sensitivity to the Higgs boson self coupling, achievable using differential cross section measurements, will result from a combination across Higgs boson production modes and decay channels. | ||
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; |
Figures & Tables | Summary | Additional Figures | References | CMS Publications |
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Figures | |
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Figure 1:
Example of a NLO Feynman diagram for $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $ production which includes the Higgs boson self-coupling. |
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Figure 2:
The BDT output distributions for the hadronic (left) and leptonic (right) channels, after pre-selection has been applied. Events with a BDT output value greater than 0.28 (0.13) are selected for the hadronic (leptonic) categories. This selection boundary is indicated by the leftmost (single) dashed line in the hadronic (leptonic) BDT output distribution. The second dashed line in the hadronic BDT output distribution shows the additional boundary at 0.61, which is used to further split the hadronic categories according to high and low ttH purity. |
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Figure 2-a:
The BDT output distributions for the hadronic (left) and leptonic (right) channels, after pre-selection has been applied. Events with a BDT output value greater than 0.28 (0.13) are selected for the hadronic (leptonic) categories. This selection boundary is indicated by the leftmost (single) dashed line in the hadronic (leptonic) BDT output distribution. The second dashed line in the hadronic BDT output distribution shows the additional boundary at 0.61, which is used to further split the hadronic categories according to high and low ttH purity. |
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Figure 2-b:
The BDT output distributions for the hadronic (left) and leptonic (right) channels, after pre-selection has been applied. Events with a BDT output value greater than 0.28 (0.13) are selected for the hadronic (leptonic) categories. This selection boundary is indicated by the leftmost (single) dashed line in the hadronic (leptonic) BDT output distribution. The second dashed line in the hadronic BDT output distribution shows the additional boundary at 0.61, which is used to further split the hadronic categories according to high and low ttH purity. |
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Figure 3:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 3-a:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 3-b:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 3-c:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 3-d:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 3-e:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 3-f:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three lowest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [0,45] GeV, [45,80] GeV and [80,120] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 4:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three highest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [120,200] GeV, [200,350] GeV and [350,$\infty $] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 4-a:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three highest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [120,200] GeV, [200,350] GeV and [350,$\infty $] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 4-b:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three highest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [120,200] GeV, [200,350] GeV and [350,$\infty $] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 4-c:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three highest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [120,200] GeV, [200,350] GeV and [350,$\infty $] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 4-d:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three highest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [120,200] GeV, [200,350] GeV and [350,$\infty $] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 4-e:
Best-fit signal (S) + background (B) models for the reconstruction-level categories in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ hadronic channel, in the three highest $ {{p_{\mathrm {T}}} ^{\gamma \gamma}} $ bins: [120,200] GeV, [200,350] GeV and [350,$\infty $] GeV. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5-a:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5-b:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5-c:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5-d:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5-e:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 5-f:
Best-fit signal (S) + background (B) models for each reconstruction-level category in the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ leptonic channel. A pseudo-data set is thrown from the best-fit functions, represented by the black points. The one (green) and two (yellow) standard deviation bands show the uncertainties in the background component of the fit. The residual plots, pseudo-data minus the background component, are shown in the lower panels. |
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Figure 6:
The expected differential $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $+$ {{\mathrm {t}} {\mathrm {H}}} $ cross sections times branching ratio, along with their respective uncertainties, in bins of $ {p_{\mathrm {T}}} ^{{\mathrm {H}}}$. These are for the fiducial region of phase space defined in the bottom left of the plot. The error bars on the black points include the statistical uncertainty, the experimental systematic uncertainties and the theoretical uncertainties related to the $ {{\mathrm {g}} {\mathrm {g}} {\mathrm {H}}} $ and V$ {\mathrm {H}} $ yields. The theoretical uncertainties in the inclusive $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}}+{{\mathrm {t}} {\mathrm {H}}} $ cross section and those effecting the shape of the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} + {{\mathrm {t}} {\mathrm {H}}} $ $p_{\mathrm{T}}^{\mathrm{H}}$ spectrum, originating from the uncertainty in the QCD scales, are shown by the shaded yellow regions. Contributions from the individual hadronic and leptonic channels are shown in red and purple respectively. The cross section for the $ {p_{\mathrm {T}}} ^{{\mathrm {H}}}$ = [350,$\infty $] GeV bin is scaled by the width of the previous bin. Additionally, the expected differential $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $ + $ {{\mathrm {t}} {\mathrm {H}}} $ cross sections for anomalous values of the Higgs boson self-coupling ($\kappa _\lambda = $ 10 and $\kappa _\lambda = -5$) are shown by the horizontal dashed lines. |
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Figure 7:
Results of the likelihood scan in $\kappa _\lambda $. The individual contributions of the statistical and systematic uncertainties are separated by performing a likelihood scan with all systematics removed. The observed deviation from the statistical uncertainty only curve is driven by the theoretical systematic uncertainties in the Higgs boson production yields. Additionally, the contributions from the hadronic and leptonic channels have been separated, shown in red and purple, respectively. |
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Figure 8:
Results of the two-dimensional likelihood scan in $\kappa _\lambda $-vs-$\mu _{{\mathrm {H}}}$, where $\mu _{{\mathrm {H}}}$ allows all Higgs boson production modes to scale relative to the SM prediction. The 68% and 95% confidence level contours are shown by the solid and dashed lines respectively. The SM expectation is shown by the black cross. |
Tables | |
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Table 1:
Summary of the input variables for both the hadronic and leptonic BDT classifiers. |
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Table 2:
Number of events remaining at the subsequent stages of the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $ + $ {{\mathrm {t}} {\mathrm {H}}} $ hadronic selection. Also shown are the respective efficiencies of selection at each stage. The BDT efficiency, $\epsilon _{\textrm {BDT}}$, is defined as the ratio of the number of events remaining after the cut on the BDT output, to the number of events remaining after pre-selection. All event yields are normalised to 3 ab$^{-1}$. |
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Table 3:
Number of events remaining at the subsequent stages of the $ {{\mathrm {t}} {\mathrm {t}} {\mathrm {H}}} $ + $ {{\mathrm {t}} {\mathrm {H}}} $ leptonic selection. Also shown are the respective efficiencies of selection at each stage. The BDT efficiency, $\epsilon _{\textrm {BDT}}$, is defined as the ratio of the number of events remaining after the cut on the BDT output, to the number of events remaining after pre-selection. All event yields are normalised to 3 ab$^{-1}$. |
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Table 4:
The kinematic bins in which the differential cross sections are measured. |
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Table 5:
The 68% and 95% confidence level intervals for $\kappa _\lambda $ for different integrated luminosities recorded by the CMS Phase-2 detector at the HL-LHC, assuming constant detector performance. The 95% upper limit for $\mathcal {L}_{\textrm {int}}$ = 1 ab$^{-1}$ goes outside of the valid region, and is specified as 20+ in the table. |
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Table 6:
The 1$\sigma $ uncertainties in $\mu _H$ and the 95% confidence level intervals for $\kappa _\lambda $, when the other parameter is profiled or fixed to the SM prediction. |
Summary |
The precision of ${\mathrm{t}\mathrm{t}\mathrm{H}} +{\mathrm{t}\mathrm{H}} $, ${\mathrm{H}\to\gamma\gamma} $ differential cross section measurements, at the HL-LHC with the CMS Phase-2 detector, have been determined as a function of $p_T^H$. The analysis has been conducted using a simulated event sample corresponding to 3 ab$^{-1}$ of pp collision data under HL-LHC conditions. A combination of the hadronic and leptonic top decay channels is performed to maximise the sensitivity of the cross section measurements to the Higgs boson self-coupling. With the data expected by the end of the HL-LHC, the cross section in bins of ${p_{\mathrm{T}}}^{\mathrm{H}}$ can be measured within uncertainties of 20-40%, depending on the ${p_{\mathrm{T}}}$ range. When deviations from the standard model prediction for the ${\mathrm{t}\mathrm{t}\mathrm{H}} $+${\mathrm{t}\mathrm{H}} $ ${p_{\mathrm{T}}}^{\mathrm{H}}$ differential cross section are interpreted as modifications of the Higgs boson self-coupling, $\kappa_\lambda$, these measurements exclude values outside of the range -4.1 $ < \kappa_\lambda < $ 14.1, at the 95% confidence level. Furthermore, it has been shown such measurements still provide sensitivity to $\kappa_\lambda$, without exploiting the overall normalisation of the ${p_{\mathrm{T}}}^{\mathrm{H}}$ spectrum, thus allowing for other effects, such as the presence of anomalous top-Higgs couplings. This property is unique to differential cross section measurements. This analysis indicates that additional sensitivity to the Higgs boson self-coupling is available through studies of the differential cross section of single Higgs boson production in association with top quarks. It should be noted that the ultimate sensitivity to the Higgs boson self-coupling, achievable at the HL-LHC, will result from a combination of analyses such as that described in this note with other Higgs decay channels and production modes, and with direct searches for double Higgs boson production. |
Additional Figures | |
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Additional Figure 1:
Results of the likelihood scan in $\kappa _\lambda $ for different uncertainty scenarios. The nominal result, with all systematic uncertainties included, is shown by the solid black curve. The result when only including experimental systematic uncertainties is shown by the red curve. The statistical uncertainty only curve is shown by the dashed black line. |
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Additional Figure 2:
Results of the likelihood scan in $\kappa _\lambda $ for different integrated luminosities recorded by the CMS Phase-2 detector. |
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Additional Figure 3:
Results of the likelihood scan in $\kappa _\lambda $, when profiling $\mu_{\mathrm{H}}$ (blue) and fixing $\mu_{\mathrm{H}}$ to the standard model prediction (black). |
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Additional Figure 4:
Results of the likelihood scan in $\mu_{\mathrm{H}}$, when profiling $\kappa _\lambda $ (blue) and fixing $\kappa _\lambda $ to the standard model prediction (black). |
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 | PL12 (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 | PR145 (1966) 1156 | |
6 | T. W. B. Kibble | Symmetry breaking in non-Abelian gauge theories | PR155 (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 at a mass of 125 GeV with the CMS experiment 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) 81 | CMS-HIG-12-036 1303.4571 |
10 | ATLAS and CMS Collaborations | Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC $ pp $ collision data at $ \sqrt{s} = $ 7 and 8 TeV | JHEP 08 (2016) 45 | 1606.02266 |
11 | ATLAS Collaboration | Combined measurements of Higgs boson production and decay using up to 80 fb$ ^{-1} $ of proton--proton collision data at $ \sqrt{s}= $ 13 TeV collected with the ATLAS experiment | ATLAS-CONF-2018-031, CERN, Geneva, Jul | |
12 | CMS Collaboration | Combined measurements of the Higgs boson's couplings at $ \sqrt{s}= $ 13 TeV | CMS-PAS-HIG-17-031 | CMS-PAS-HIG-17-031 |
13 | ATLAS Collaboration | Combination of searches for Higgs boson pairs in $ pp $ collisions at 13 TeV with the ATLAS experiment. | ATLAS-CONF-2018-043, CERN, Geneva, Sep | |
14 | CMS Collaboration | Combination of searches for Higgs boson pair production in proton-proton collisions at $ \sqrt{s} = $ 13 TeV | CMS-PAS-HIG-17-030 | CMS-PAS-HIG-17-030 |
15 | G. Degrassi, P. P. Giardino, F. Maltoni, and D. Pagani | Probing the Higgs self coupling via single Higgs production at the LHC | JHEP 12 (2016) 080 | 1607.04251 |
16 | F. Maltoni, D. Pagani, A. Shivaji, and X. Zhao | Trilinear Higgs coupling determination via single-Higgs differential measurements at the LHC | EPJC77 (2017), no. 12, 887 | 1709.08649 |
17 | W. Bizon, M. Gorbahn, U. Haisch, and G. Zanderighi | Constraints on the trilinear Higgs coupling from vector boson fusion and associated Higgs production at the LHC | JHEP 07 (2017) 083 | 1610.05771 |
18 | M. Gorbahn and U. Haisch | Indirect probes of the trilinear Higgs coupling: $ gg \to h $ and $ h \to \gamma \gamma $ | JHEP 10 (2016) 094 | 1607.03773 |
19 | S. Di Vita et al. | A global view on the Higgs self-coupling | JHEP 09 (2017) 069 | 1704.01953 |
20 | M. McCullough | An Indirect Model-Dependent Probe of the Higgs Self-Coupling | PRD90 (2014), no. 1, 015001 | 1312.3322 |
21 | A. Shivaji and X. Zhao | , 2018 [Online; accessed 12-Sep-2018] | ||
22 | CMS Collaboration | Observation of $ \mathrm{t\bar{t}H} $ production | PRL 120 (2018) 231801 | CMS-HIG-17-035 1804.02610 |
23 | ATLAS Collaboration | Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector | PLB784 (2018) 173--191 | 1806.00425 |
24 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
25 | G. Apollinari et al. | High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report | ||
26 | CMS Collaboration | Technical Proposal for the Phase-II Upgrade of the CMS Detector | CERN-LHCC-2015-010 | |
27 | CMS Collaboration | The Phase-2 Upgrade of the CMS Tracker | CDS | |
28 | CMS Collaboration | The Phase-2 Upgrade of the CMS Barrel Calorimeter | CDS | |
29 | CMS Collaboration | The Phase-2 Upgrade of the CMS Endcap Calorimeter | CDS | |
30 | CMS Collaboration | The Phase-2 Upgrade of the CMS Muon Detectors | CDS | |
31 | CMS Collaboration | Technical proposal for a MIP timing detector in the CMS experiment phase 2 upgrade | CDS | |
32 | CMS Collaboration | CMS Phase-2 Object Performance | ||
33 | 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 |
34 | P. Nason and C. Oleari | NLO higgs boson production via vector-boson fusion matched with shower in POWHEG | JHEP 02 (2010) 037 | 0911.5299 |
35 | 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 |
36 | T. Sjostrand, S. Mrenna, and P. Z. Skands | A Brief Introduction to PYTHIA 8.1 | CPC 178 (2008) 852--867 | 0710.3820 |
37 | LHC Higgs Cross Section Working Group Collaboration | Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector | 1610.07922 | |
38 | C. Anastasiou et al. | Higgs boson gluon--fusion production at threshold in N$ ^3 $LO QCD | PLB 737 (2014) 325 | 1403.4616 |
39 | T. Gleisberg et al. | Event generation with SHERPA 1.1 | JHEP 02 (2009) 007 | 0811.4622 |
40 | DELPHES 3 Collaboration | DELPHES 3, A modular framework for fast simulation of a generic collider experiment | JHEP 02 (2014) 057 | 1307.6346 |
41 | GEANT4 Collaboration | GEANT4 -- a simulation toolkit | NIMA 506 (2003) 250 | |
42 | CMS Collaboration | Performance of Photon Reconstruction and Identification with the CMS Detector in Proton-Proton Collisions at sqrt(s) = 8 TeV | JINST 10 (2015), no. 08, P08010 | CMS-EGM-14-001 1502.02702 |
43 | CMS Collaboration | Particle-flow reconstruction and global event description with the CMS detector | JINST 12 (2017), no. 10, P10003 | CMS-PRF-14-001 1706.04965 |
44 | M. Cacciari, G. P. Salam, and G. Soyez | The anti-$ {k_{\mathrm{T}}} $ jet clustering algorithm | JHEP 04 (2008) 063 | 0802.1189 |
45 | M. Cacciari, G. P. Salam, and G. Soyez | FastJet user manual | EPJC 72 (2012) 1896 | 1111.6097 |
46 | D. Bertolini, P. Harris, M. Low, and N. Tran | Pileup Per Particle Identification | JHEP 10 (2014) 059 | 1407.6013 |
47 | CMS Collaboration | Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV | JINST 13 (2018), no. 05, P05011 | CMS-BTV-16-002 1712.07158 |
48 | CMS Collaboration | Measurements of Higgs boson properties in the diphoton decay channel in proton-proton collisions at $ \sqrt{s} = $ 13 TeV | CMS-HIG-16-040 1804.02716 |
|
49 | CMS Collaboration | Combined measurement and interpretation of differential Higgs boson production cross sections at $ \sqrt{s} = $ 13 TeV | CMS-PAS-HIG-17-028 | CMS-PAS-HIG-17-028 |
50 | CMS UPSG group | , 2018 [Online; accessed 31 Oct. 2018] |
Compact Muon Solenoid LHC, CERN |