The data and fitted signal and background distributions for the $D_{b\overline{b}}$-subleading jet regressed mass for the ggF BDT event category 2. The SM $HH$ ($\kappa_{2V}=\kappa_{V}=\kappa_{\lambda}=1$) signal is scaled to the best fit signal strength $\mu = 3.5$.

The data and fitted signal and background distributions for the $D_{b\overline{b}}$-subleading jet regressed mass for the ggF BDT event category 3. The SM $HH$ ($\kappa_{2V}=\kappa_{V}=\kappa_{\lambda}=1$) signal is scaled to the best fit signal strength $\mu = 3.5$.

The data and fitted signal and background distributions for the $D_{b\overline{b}}$-subleading jet regressed mass for the ggF QCD multijet background control region. The SM $HH$ ($\kappa_{2V}=\kappa_{V}=\kappa_{\lambda}=1$) signal is scaled to the best fit signal strength $\mu = 3.5$.

The data in the ggF BDT event category 1 after subtracting all background processes except the QCD multijet one compared to the QCD multijet background prediction derived from the dedicated control region.

The data in the ggF BDT event category 2 after subtracting all background processes except the QCD multijet one compared to the QCD multijet background prediction derived from the dedicated control region.

The data in the ggF BDT event category 3 after subtracting all background processes except the QCD multijet one compared to the QCD multijet background prediction derived from the dedicated control region.

The data and expected background distributions in the $t\overline{t}$ control region of the $D_{b\overline{b}}$-leading jet $m_{ ext{SD}}$.

The data and expected background distributions in the $t\overline{t}$ control region of the $D_{b\overline{b}}$-leading jet $D_{b\overline{b}}$.

The data and expected background distributions in the $t\overline{t}$ control region of $m_{HH}$.

The data and expected background distributions in the $t\overline{t}$ control region of $p_{\text{T} j_{1}}/m_{HH}$.

Expected and observed 95% CL upper limits on $HH$ production with respect to the SM expectation ($\kappa_{\lambda}=\kappa_{t}=\kappa_{V}=\kappa_{2V}=1$) in the individual ggF and VBF search categories and their combination.

Expected and observed 95% CL upper limits on $HH$ production with respect to the expectation for $\kappa_{\lambda}=\kappa_{t}=\kappa_{V}=1$, $\kappa_{2V}=0$ in the individual ggF and VBF search categories and their combination.

Observed and expected 95% CL exclusion limit on the product of the inclusive $HH$ production cross section and the branching fraction into $b\overline{b}b\overline{b}$ as a function of $\kappa_{\lambda}$ with other couplings fixed to the SM values.

Observed and expected 95% CL exclusion limit on the product of the inclusive $HH$ production cross section and the branching fraction into $b\overline{b}b\overline{b}$ as a function of $\kappa_{2V}$ with other couplings fixed to the SM values.

Observed and expected 95% CL exclusion limit on the product of the inclusive $HH$ production cross section and the branching fraction into $b\overline{b}b\overline{b}$ as a function of $\kappa_{V}$ with other couplings fixed to the SM values.

Observed and expected 95% CL exclusion limit on the product of the VBF $HH$ production cross section and the branching fraction into $b\overline{b}b\overline{b}$ as a function of $\kappa_{2V}$ with other couplings fixed to the SM values.

Observed and expected 95% CL exclusion limit on the product of the VBF $HH$ production cross section and the branching fraction into $b\overline{b}b\overline{b}$ as a function of $\kappa_{V}$ with other couplings fixed to the SM values.

Two-parameter profile likelihood test statistic ($-2\Delta\ln\mathcal{L}$) scan in data as a function of $\kappa_{2V}$ and $\kappa_{V}$.

Major sources of uncertainty in the measurement of the signal strength modifier $\mu$, and their observed impact ($\Delta\mu$) from a fit to the combined data set.