Distribution of the NN output in the $\geq$1fj$\,$SR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.

Distribution of the NN output in the $t\bar{t}\gamma\,$CR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.

Total event yield in the $W\gamma\,$CR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.

Distribution of the scalar sum of the jet transverse momenta in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.

Distribution of the $\eta$ of the $b$-tagged jet in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.

Distribution of the reconstructed top-quark mass in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.

Distribution of the $p_{\mathrm{T}}$ of the top-quark+photon system in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the photon $p_{\mathrm{T}}$ in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the photon $\eta$ in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.

Distribution of the scalar sum of the jet transverse momenta in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the invariant mass of the $b$-tagged jet and the highest-$p_{\mathrm{T}}$ forward jet in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of $p_{\mathrm{T}}$ of the highest-$p_{\mathrm{T}}$ forward jet in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the difference in $\eta$ between the highest-$p_{\mathrm{T}}$ forward jet and the photon in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the energy of the system formed by the highest-$p_{\mathrm{T}}$ forward jet and the photon in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.

Distribution of the $\eta$ of the $b$-tagged jet in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.

Distribution of the reconstructed top-quark mass in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.

Distribution of the $p_{\mathrm{T}}$ of the top-quark and photon system in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the photon $p_{\mathrm{T}}$ in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.

Distribution of the photon $\eta$ in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.

Ordered list of the 30 systematic uncertainties with the largest impact on the measured signal normalisation in the fit to data in the parton-level measurement considered as nuisance parameters (NPs) in the profile-likelihood fit. The column "NP value, error" corresponds to the nominal best-fit values and the corresponding uncertainties. The impact of each NP, $\Delta\sigma$/$\sigma_{\mathrm{pred}}$, is computed by comparing the nominal best-fit value of the POI ($\sigma$/$\sigma_{\mathrm{pred}}$) with the result of the fits when fixing the considered NP to its best-fit value shifted by its pre-fit and post-fit uncertainties. The corresponding impacts are listed in the "POI impact prefit high/low" and "POI impact high/low" columns, respectively. The "MC stat." NPs represent the MC statistical uncertainty and they enter the likelihood with a Poisson term, while all the other NPs enter the likelihood via a Gaussian term.

Ordered list of the 30 systematic uncertainties with the largest impact on the measured signal normalisation in the fit to data in the particle-level measurement considered as nuisance parameters (NPs) in the profile-likelihood fit. The column "NP value, error" corresponds to the nominal best-fit values and the corresponding uncertainties. The impact of each NP, $\Delta\sigma$/$\sigma_{\mathrm{pred}}$, is computed by comparing the nominal best-fit value of the POI ($\sigma$/$\sigma_{\mathrm{pred}}$) with the result of the fits when fixing the considered NP to its best-fit value shifted by its pre-fit and post-fit uncertainties. The corresponding impacts are listed in the "POI impact prefit high/low" and "POI impact high/low" columns, respectively. The "MC stat." NPs represent the MC statistical uncertainty and they enter the likelihood with a Poisson term, while all the other NPs enter the likelihood via a Gaussian term.

This table lists the kinematic requirements on parton-level objects used to define of the fiducial phase space for the parton-level measurement. Frixione isolation ($\href{https://arxiv.org/abs/hep-ph/9801442}{\text{hep-ph/9801442}}$) with a chosen radius of $\Delta R = 0.2$ is applied to photons ($\gamma$). The measured fiducial parton-level cross section is $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b) = 688\pm 23(\text{stat.})^{+75}_{-71}(\text{syst.})\,$fb.

This table lists the kinematic requirements on particle-level objects used to define of the fiducial phase space for the particle-level measurement. The particle level objects are photons ($\gamma$) not from a hadron decay, neutrinos not from a hadron decay ($\nu$), prompt electrons and muons ($\ell$) "dressed" by adding close-by ($\Delta R < 0.1$) photons, and anti-$k_t$ $R = 0.4$ jets built from stable particles ($\tau > 30\,$ps) and tau leptons excluding neutrinos and prompt dressed muons. Jets are $b$-tagged ($b$-jet) using ghost-matched $b$-hadrons with $p_{\text{T}} > 5\,$GeV. Apart from the kinematic requirements, isolation and overlap removal criteria are applied. Jets within $\Delta R = 0.4$ of a photon are removed if the $p_{\text{T}}$ of charged particles within $\Delta R = 0.3$ of the photon is smaller than $10\,\%$ of its $p_{\text{T}}$. Jets within $\Delta R = 0.4$ of a lepton are removed. Events are removed where a photon is close ($\Delta R < 0.4$) to a lepton or a surviving jet. The measured fiducial particle-level cross section is $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b)+\sigma_{t(\rightarrow l\nu b\gamma)q} = 303\pm 9(\text{stat.})^{+33}_{-32}(\text{syst.})\,$fb.

Feynman diagrams of $\mathrm{Z'}\to\mu^{-}\mu^{+}$ with a $\mathrm{Z'}$ boson produced via $\mathrm{s}\overline{\mathrm{b}}\to\mathrm{Z'}$, with one $\mathrm{b}$ quark and one $\overline{\mathrm{s}}$ quark in the final state.

Distribution of $\min(m_{\mu\mathrm{b}})$ as obtained from simulation in events with $N_{\mathrm{b}} \geq 1$ passing all the other selection requirements. In this search, we require $\min(m_{\mu\mathrm{b}})>175~\mathrm{GeV}$. The stacked histogram displays the expected distribution from the simulation of the SM backgrounds, while the overlaid open histograms illustrate the size and shape of the $\mathrm{Z'}$ contribution from the LFU model described in Eq. (1), for several $\mathrm{Z'}$ mass hypotheses. For illustrative purposes, we choose couplings $|g_{\ell}| = |g_{\nu}| = |g_{\mathrm{b}}| = 0.03$ and $\delta_{\mathrm{bs}}=0$. The contribution of background processes other than DY and $\mathrm{t}\overline{\mathrm{t}}$ is so small that it is only barely visible at the bottom of the stacked histogram. The hatched region indicates the statistical uncertainty arising from the limited size of the SM simulated samples. Histograms are normalized to unit area.

Distributions of $m_{\mu\mu}$ in the $N_{\mathrm{b}}=1$ event category. The stacked histogram displays the expected distribution from the SM background simulation. The overlaid open distributions illustrate the $\mathrm{Z'}$ contribution from the LFU model at $|g_{\ell}| = |g_{\nu}| = |g_{\mathrm{b}}| = 0.03$ and $\delta_{\mathrm{bs}}=0$ for a variety of $\mathrm{Z'}$ mass hypotheses. The observed data are shown as black points with statistical error bars. The hatched region indicates the statistical uncertainty arising from the limited size of the SM simulated samples. The size of the bins increases as a function of $m_{\mu\mu}$. In extracting the results of the search, the background is estimated directly from data, so the SM background simulation is only illustrative in these distributions.

Distributions of $m_{\mu\mu}$ in the $N_{\mathrm{b}}\geq 2$ event category. The stacked histogram displays the expected distribution from the SM background simulation. The overlaid open distributions illustrate the $\mathrm{Z'}$ contribution from the LFU model at $|g_{\ell}| = |g_{\nu}| = |g_{\mathrm{b}}| = 0.03$ and $\delta_{\mathrm{bs}}=0$ for a variety of $\mathrm{Z'}$ mass hypotheses. The observed data are shown as black points with statistical error bars. The hatched region indicates the statistical uncertainty arising from the limited size of the SM simulated samples. The size of the bins increases as a function of $m_{\mu\mu}$. In extracting the results of the search, the background is estimated directly from data, so the SM background simulation is only illustrative in these distributions.

Invariant mass $m_{\mu\mu}$ distributions in the $N_{\mathrm{b}} = 1$ category, shown together with the corresponding selected background functional forms used as input to the $discrete~profiling$ method when probing the $m_{\mathrm{Z'}}=500~\mathrm{GeV}$ hypothesis. The expected signal distribution for the LFU model described in Eq. (1), with couplings $|g_{\ell}| = |g_{\nu}| = |g_{\mathrm{b}}| = 0.03$ and $\delta_{\mathrm{bs}}=0$, is overlaid. The displayed mass range corresponds to the fit window used for this $m_{\mathrm{Z'}}$ hypothesis, which is $\pm 10\, \sigma_{\mathrm{mass}}$ around the probed $m_{\mathrm{Z'}}$ value. While the likelihood fits are performed on unbinned data, here we present the data in binned histograms with binning chosen to reflect the size of $\sigma_{\mathrm{mass}}$.

Invariant mass $m_{\mu\mu}$ distributions in the $N_{\mathrm{b}} \geq 2$ category, shown together with the corresponding selected background functional forms used as input to the $discrete~profiling$ method when probing the $m_{\mathrm{Z'}}=500~\mathrm{GeV}$ hypothesis. The expected signal distribution for the LFU model described in Eq. (1), with couplings $|g_{\ell}| = |g_{\nu}| = |g_{\mathrm{b}}| = 0.03$ and $\delta_{\mathrm{bs}}=0$, is overlaid. The displayed mass range corresponds to the fit window used for this $m_{\mathrm{Z'}}$ hypothesis, which is $\pm 10\, \sigma_{\mathrm{mass}}$ around the probed $m_{\mathrm{Z'}}$ value. While the likelihood fits are performed on unbinned data, here we present the data in binned histograms with binning chosen to reflect the size of $\sigma_{\mathrm{mass}}$.

Exclusion limits at $95\%$ CL on the number of selected BSM events with $N_{\mathrm{b}} \geq 1$ as functions of $m_{\mathrm{Z'}}$ for $f_{2\mathrm{b}}=0$. The quantity $f_{2\mathrm{b}}$ is the fraction of BSM events passing the analysis selection that have at least two $\mathrm{b}$ quark jets. The solid black (dashed red) curve represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing $68~(95)\%$ of the distribution of limits expected under the background-only hypothesis.

Exclusion limits at $95\%$ CL on the number of selected BSM events with $N_{\mathrm{b}} \geq 1$ as functions of $m_{\mathrm{Z'}}$ for $f_{2\mathrm{b}}=0.25$. The quantity $f_{2\mathrm{b}}$ is the fraction of BSM events passing the analysis selection that have at least two $\mathrm{b}$ quark jets. The solid black (dashed red) curve represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing $68~(95)\%$ of the distribution of limits expected under the background-only hypothesis.

Exclusion limits at $95\%$ CL on the number of selected BSM events with $N_{\mathrm{b}} \geq 1$ as functions of $m_{\mathrm{Z'}}$ for $f_{2\mathrm{b}}=0.75$. The quantity $f_{2\mathrm{b}}$ is the fraction of BSM events passing the analysis selection that have at least two $\mathrm{b}$ quark jets. The solid black (dashed red) curve represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing $68~(95)\%$ of the distribution of limits expected under the background-only hypothesis.

Exclusion limits at $95\%$ CL on the number of selected BSM events with $N_{\mathrm{b}} \geq 1$ as functions of $m_{\mathrm{Z'}}$ for $f_{2\mathrm{b}}=1$. The quantity $f_{2\mathrm{b}}$ is the fraction of BSM events passing the analysis selection that have at least two $\mathrm{b}$ quark jets. The solid black (dashed red) curve represents the observed (median expected) exclusion. The inner green (outer yellow) band indicates the region containing $68~(95)\%$ of the distribution of limits expected under the background-only hypothesis.

Observed (solid) and median expected (dashed) exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution, marked by the dotted curves. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=350~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=350~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=350~\mathrm{GeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=700~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=700~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=700~\mathrm{GeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $\delta_{\mathrm{bs}}=0$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed (solid) and median expected (dashed) exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution, marked by the dotted curves. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=350~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=350~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=350~\mathrm{GeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=700~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=700~\mathrm{GeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=700~\mathrm{GeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The exclusion limits are given up to coupling values at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid. The enclosed regions are excluded.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{b}}|$--$|g_{\ell}|$ plane for the LFU model, with $|\delta_{\mathrm{bs}}|=0.25$ and $|g_{\nu}|=|g_{\ell}|$, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width is equal to half of the $\mu\mu$ invariant mass resolution. Beyond these coupling values, the narrow width approximation intrinsic to the search strategy is not considered valid.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$. The solid black (dashed red) curves represent the observed (median expected) exclusions. The dotted curves denote the coupling values at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid. The region enclosed between the solid black (dashed red) and dotted curves is (expected to be) excluded. The dotted curve for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$ lies beyond the displayed $|g_{\mathrm{Z'}}|$ range and is, therefore, not shown. The shaded blue area represents the region preferred from the global fit in JHEP 04 (2023) 033 at $95\%$ CL. The region above the green dash-dotted curve is incompatible at $95\%$ CL with the measurement of the mass difference between the mass eigenstates of the neutral $\mathrm{B}_\mathrm{s}$ mesons.

Observed exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$.

Expected exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=500~\mathrm{GeV}$.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The solid black (dashed red) curves represent the observed (median expected) exclusions. The dotted curves denote the coupling values at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid. The region enclosed between the solid black (dashed red) and dotted curves is (expected to be) excluded. The shaded blue area represents the region preferred from the global fit in JHEP 04 (2023) 033 at $95\%$ CL. The region above the green dash-dotted curve is incompatible at $95\%$ CL with the measurement of the mass difference between the mass eigenstates of the neutral $\mathrm{B}_\mathrm{s}$ mesons.

Observed exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$.

Expected exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The solid black (dashed red) curves represent the observed (median expected) exclusions. The dotted curves denote the coupling values at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid. The region enclosed between the solid black (dashed red) and dotted curves is (expected to be) excluded. The shaded blue area represents the region preferred from the global fit in JHEP 04 (2023) 033 at $95\%$ CL. The region above the green dash-dotted curve is incompatible at $95\%$ CL with the measurement of the mass difference between the mass eigenstates of the neutral $\mathrm{B}_\mathrm{s}$ mesons.

Observed exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$.

Expected exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=1.5~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The solid black (dashed red) curves represent the observed (median expected) exclusions. The dotted curves denote the coupling values at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid. The region enclosed between the solid black (dashed red) and dotted curves is (expected to be) excluded. The shaded blue area represents the region preferred from the global fit in JHEP 04 (2023) 033 at $95\%$ CL. The region above the green dash-dotted curve is incompatible at $95\%$ CL with the measurement of the mass difference between the mass eigenstates of the neutral $\mathrm{B}_\mathrm{s}$ mesons.

Observed exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$.

Expected exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$.

Exclusion limits at $95\%$ CL in the $|\theta_{23}|$--$|g_{\mathrm{Z'}}|$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for $m_{\mathrm{Z'}}=2~\mathrm{TeV}$. The coupling values are shown at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{Z'}}|$--$m_{\mathrm{Z'}}$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for a fixed value of $\theta_{23}=0$. The solid black (dashed red) curve represents the observed (median expected) exclusion. The dotted curve denotes the coupling values at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid. The region enclosed between the solid black (dashed red) and the dotted curves is (expected to be) excluded. The shaded blue area represents the $|g_{\mathrm{Z'}}|$ range preferred from a global fit in JHEP 04 (2023) 033 at $95\%$ CL.

Observed exclusion limits at $95\%$ CL in the $|g_{\mathrm{Z'}}|$--$m_{\mathrm{Z'}}$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for a fixed value of $\theta_{23}=0$.

Expected exclusion limits at $95\%$ CL in the $|g_{\mathrm{Z'}}|$--$m_{\mathrm{Z'}}$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for a fixed value of $\theta_{23}=0$.

Exclusion limits at $95\%$ CL in the $|g_{\mathrm{Z'}}|$--$m_{\mathrm{Z'}}$ plane for the $B_{3}\!-\!L_{2}$ model from JHEP 04 (2023) 033, for a fixed value of $\theta_{23}=0$. The coupling values are shown at which the $\mathrm{Z'}$ width equals one half of the $\mu\mu$ invariant mass resolution. For larger values of the couplings, the narrow width approximation intrinsic to the search strategy is not considered valid.

Normalisation factors for the major background processes and ttW ($\Delta \eta < 0$) from the fit using only statistical uncertainties (fixing Nuisance Parameters (NP) to their fitted values) to data in all analysis regions.

Normalisation factors for the major background processes and ttW ($\Delta \eta < 0$) from the fit using using both statistical and systematic uncertainties to data in all analysis regions.

Correlation matrix between the Normalisation Factors in the fit using only statistical uncertainties (fixing Nuisance Parameters (NP) to their fitted values) to data in all analysis regions.

The most relevant systematic uncertainties ranked by their impact on the leptonic charge asymmetry ($A_c^{\ell}$) parameter at reconstructed level. The impact of the uncertainties is shown before and after the combined profile-likelihood fit to data in the signal and control regions. Pulls introduced by the fitting procedure are also shown. The entries shown in bold are the uncertainties of the freely floating background normalisations. ME stands for "matrix element", PS for "parton shower" and JER for "jet energy resolution". The gamma-uncertainties refer to the MC statistical uncertainties in a specific region and bin.

The most relevant systematic uncertainties ranked by their impact on the ttW Normalisation Factor ($\Delta \eta < 0$) parameter at reconstructed level. The impact of the uncertainties is shown before and after the combined profile-likelihood fit to data in the signal and control regions. Pulls introduced by the fitting procedure are also shown. ME stands for "matrix element", PS for "parton shower" and JER for "jet energy resolution". The gamma-uncertainties refer to the MC statistical uncertainties in a specific region and bin.

The predicted and observed numbers of events in the control and signal regions. The predictions are shown before the fit to data. The indicated uncertainties consider statistical as well as all experimental and theoretical systematic uncertainties. Background categories with event yields with a value of 1.0e-6 have a negligible contribution to the region and are manually set to that value.

The predicted and observed numbers of events in the control and signal regions. The predictions are shown after the fit to data. The indicated uncertainties consider statistical as well as all experimental and theoretical systematic uncertainties. Background categories with event yields with a value of 1.0e-6 have a negligible contribution to the region and are manually set to that value.

The $m_{e\mu}$ distribution of the observed data is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in red solid line, and the background component of the fit in red dotted line. Events and fit in each category are weighted by $S/(S+B)$. The one and two standard deviation uncertainty bands of the background component are shown in green and yellow. The lower panel shows the residuals after subtracting the background component of the fit from data.

Observed (expected) 95% confidence level upper limits on $\sigma(p p \to X(146) \to e \mu)$ for each individual analysis category (as shown in the left axis label) and for the combination of all analysis categories assuming the relative SM-like production cross sections of the ggH and VBF production modes.

The $m_{e\mu}$ distribution of the observed data in the category ggH cat 0 is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in solid red line, and the background component of the fit in dotted red line. The green and yellow bands represent the one and two standard deviations of the background component. The lower panel shows the residuals after subtracting the background component of the fit from data.

The $m_{e\mu}$ distribution of the observed data in the category ggH cat 1 is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in solid red line, and the background component of the fit in dotted red line. The green and yellow bands represent the one and two standard deviations of the background component. The lower panel shows the residuals after subtracting the background component of the fit from data.

The $m_{e\mu}$ distribution of the observed data in the category ggH cat 2 is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in solid red line, and the background component of the fit in dotted red line. The green and yellow bands represent the one and two standard deviations of the background component. The lower panel shows the residuals after subtracting the background component of the fit from data.

The $m_{e\mu}$ distribution of the observed data in the category ggH cat 3 is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in solid red line, and the background component of the fit in dotted red line. The green and yellow bands represent the one and two standard deviations of the background component. The lower panel shows the residuals after subtracting the background component of the fit from data.

The $m_{e\mu}$ distribution of the observed data in the category VBF cat 0 is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in solid red line, and the background component of the fit in dotted red line. The green and yellow bands represent the one and two standard deviations of the background component. The lower panel shows the residuals after subtracting the background component of the fit from data.

The $m_{e\mu}$ distribution of the observed data in the category VBF cat 1 is shown, with the $S+B$ fit at $m_{X}=146\mathrm{GeV}$ in solid red line, and the background component of the fit in dotted red line. The green and yellow bands represent the one and two standard deviations of the background component. The lower panel shows the residuals after subtracting the background component of the fit from data.

Best fit of $\sigma(p p \to X(146) \to e \mu)$ for each analysis category (black point) compared to the best fit for the combination of all analysis categories (blue line). The one standard deviation uncertainty of the per-category best fit is shown in red line and the one standard deviation uncertainty of the combined best fit is shown in green band.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.0.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.1.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.2.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.3.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.4.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.5.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.6.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.7.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.8.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 0.9.

The observed and expected 95% CL upper limits on $\sigma_{ggH,f_{VBF}}(p p \to X \to e \mu)$ and $\sigma_{VBF,f_{VBF}}(p p \to X \to e \mu)$ with $f_{VBF}$ = 1.0.

Summary of the total uncertainty in the background prediction for each SR of the tt0L-low, tt0L-high, tt1L and tt2L analysis channels in the statistical combination. Their dominant contributions are indicated by individual lines. Individual uncertainties can be correlated, and do not necessarily add up in quadrature to the total background uncertainty.

Exclusion limits for colour-neutral scalar mediator dark matter models as a function of the mediator mass $m(\phi)$ for a DM mass $m_{\chi} = 1$ GeV. Associated production of DM with both single top quarks ($tW$ and $tj$ channels) and top quark pairs is considered. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for each individual channel and their statistical combination.

Exclusion limits for colour-neutral pseudoscalar mediator dark matter models as a function of the mediator mass $m(a)$ for a DM mass $m_{\chi} = 1$ GeV. Associated production of DM with both single top quarks ($tW$ and $tj$ channels) and top quark pairs is considered. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for each individual channel and their statistical combination.

$E_{\text{T}}^{\text{miss}}$ distribution in SR0X for the tt0L-low analysis. The contributions from all SM backgrounds are shown after the profile likelihood simultaneous fit to all tt0L-low CRs, with the hatched bands representing the total uncertainty. The category '$t\bar{t}$ (other)' represents $t\bar{t}$ events without extra jets or events with extra light-flavour jets. 'Other' includes contributions from $t\bar{t}W$, $tZ$ and $tWZ$ processes. The expected distributions for selected signal models are shown as dashed lines. The overflow events are included in the last bin. The bottom panels show the ratio of the observed data to the total SM background prediction, with the hatched area representing the total uncertainty in the background prediction and the red arrows marking data outside the vertical-axis range.

$E_{\text{T}}^{\text{miss}}$ distribution in SRWX for the tt0L-low analysis. The contributions from all SM backgrounds are shown after the profile likelihood simultaneous fit to all tt0L-low CRs, with the hatched bands representing the total uncertainty. The category '$t\bar{t}$ (other)' represents $t\bar{t}$ events without extra jets or events with extra light-flavour jets. 'Other' includes contributions from $t\bar{t}W$, $tZ$ and $tWZ$ processes. The expected distributions for selected signal models are shown as dashed lines. The overflow events are included in the last bin. The bottom panels show the ratio of the observed data to the total SM background prediction, with the hatched area representing the total uncertainty in the background prediction and the red arrows marking data outside the vertical-axis range.

$E_{\text{T}}^{\text{miss}}$ distribution in SRTX for the tt0L-low analysis. The contributions from all SM backgrounds are shown after the profile likelihood simultaneous fit to all tt0L-low CRs, with the hatched bands representing the total uncertainty. The category '$t\bar{t}$ (other)' represents $t\bar{t}$ events without extra jets or events with extra light-flavour jets. 'Other' includes contributions from $t\bar{t}W$, $tZ$ and $tWZ$ processes. The expected distributions for selected signal models are shown as dashed lines. The overflow events are included in the last bin. The bottom panels show the ratio of the observed data to the total SM background prediction, with the hatched area representing the total uncertainty in the background prediction and the red arrows marking data outside the vertical-axis range.

Exclusion limits for colour-neutral scalar mediator dark matter models as a function of the mediator mass $m(\phi)$ for a DM mass $m_{\chi} = 1$ GeV. Associated production of DM with both single top quarks ($tW$ and $tj$ channels) and top quark pairs is considered. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the nominal cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for the tt0L-high and tt0L-low analyses and their statistical combination.

Exclusion limits for colour-neutral pseudoscalar mediator dark matter models as a function of the mediator mass $m(a)$ for a DM mass $m_{\chi} = 1$ GeV. Associated production of DM with both single top quarks ($tW$ and $tj$ channels) and top quark pairs is considered. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the nominal cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for the tt0L-high and tt0L-low analyses and their statistical combination.

Exclusion limits for colour-neutral scalar mediator dark matter models as a function of the mediator mass $m(\phi)$ for a DM mass $m_{\chi} = 1$ GeV. Only associated production of DM with top quark pairs is considered for this interpretation. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for each individual channel and their statistical combination.

Exclusion limits for colour-neutral pseudoscalar mediator dark matter models as a function of the mediator mass $m(a)$ for a DM mass $m_{\chi} = 1$ GeV. Only associated production of DM with top quark pairs is considered for this interpretation. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for each individual channel and their statistical combination.

Exclusion limits for colour-neutral scalar mediator dark matter models as a function of the mediator mass $m(\phi)$ for a DM mass $m_{\chi} = 1$ GeV. Only associated production of DM with top quark pairs is considered for this interpretation. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the nominal cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for the tt0L-high and tt0L-low analyses and their statistical combination.

Exclusion limits for colour-neutral pseudoscalar mediator dark matter models as a function of the mediator mass $m(a)$ for a DM mass $m_{\chi} = 1$ GeV. Only associated production of DM with top quark pairs is considered for this interpretation. The limits are calculated at 95% CL and are expressed in terms of the ratio of the excluded cross section to the nominal cross section for a coupling assumption of $g = g_q = g_{\chi} = 1$. The solid (dashed) lines show the observed (expected) exclusion limits for the tt0L-high and tt0L-low analyses and their statistical combination.

Representative fit distribution in the different flavour leptons signal region for the tt2L analysis: each bin of such distribution, starting from the red arrow, corresponds to a single SR included in the fit. 'FNP' includes the contribution from fake/non-prompt lepton background arising from jets (mainly $\pi/K$, heavy-flavour hadron decays and photon conversion) misidentified as leptons, estimated in a purely data-driven way. 'Other' includes contributions from $t\bar{t}W$, $tZ$ and $tWZ$ processes. The total uncertainty in the SM expectation is represented with hatched bands and the expected distributions for selected signal models are shown as dashed lines.

Signal acceptance in SR0X, SRWX and SRTX for simplified DM+$t\bar{t}$ model, defined as the number of accepted events at generator level in signal Monte Carlo simulation divided by the total number of events in the sample.

Signal acceptance in SR0X, SRWX and SRTX for simplified DM+$tW$ model, defined as the number of accepted events at generator level in signal Monte Carlo simulation divided by the total number of events in the sample.

Signal acceptance in SR0X, SRWX and SRTX for simplified DM+$tj$ model, defined as the number of accepted events at generator level in signal Monte Carlo simulation divided by the total number of events in the sample.

Signal efficiency in SR0X, SRWX and SRTX for simplified DM+$t\bar{t}$ model, defined as the number of selected reconstructed events divided by the acceptance.

Signal efficiency in SR0X, SRWX and SRTX for simplified DM+$tW$ model, defined as the number of selected reconstructed events divided by the acceptance.

Signal efficiency in SR0X, SRWX and SRTX for simplified DM+$tj$ model, defined as the number of selected reconstructed events divided by the acceptance.

Cutflow for the reference point DM+$t\bar{t}$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SR0X. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 2045000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$t\bar{t}$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SRWX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 2045000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$t\bar{t}$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SRTX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 2045000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$t\bar{t}$ $m(a, \chi) = (10, 1)$ GeV in signal region SR0X. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 400000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$t\bar{t}$ $m(a, \chi) = (10, 1)$ GeV in signal region SRWX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 400000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$t\bar{t}$ $m(a, \chi) = (10, 1)$ GeV in signal region SRTX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 400000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tW$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SR0X. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 120000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tW$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SRWX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 120000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tW$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SRTX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 120000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tW$ $m(a, \chi) = (10, 1)$ GeV in signal region SR0X. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 100000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tW$ $m(a, \chi) = (10, 1)$ GeV in signal region SRWX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 100000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tW$ $m(a, \chi) = (10, 1)$ GeV in signal region SRTX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 100000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tj$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SR0X. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 169000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tj$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SRWX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 169000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tj$ $m(\phi, \chi) = (10, 1)$ GeV in signal region SRTX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 169000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tj$ $m(a, \chi) = (10, 1)$ GeV in signal region SR0X. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 140000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tj$ $m(a, \chi) = (10, 1)$ GeV in signal region SRWX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 140000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Cutflow for the reference point DM+$tj$ $m(a, \chi) = (10, 1)$ GeV in signal region SRTX. The column labelled 'weighted' shows the event yield including all correction factors applied to simulation, and is normalised to 139 fb$^{-1}$. A notable exception concerns the 'weighted' numbers in the first and the second row, labelled 'Total' and 'Filtered', which correspond to $\mathcal{L}\cdot\sigma$ and $\mathcal{L}\cdot\sigma\cdot\epsilon$ expected, respectively. The 'Skim' selection requires the $p_{\text{T}}$ of the leading four jets to be above (80, 60, 40, 40) GeV, the missing transverse momentum $E_{\text{T}}^{\text{miss}} > 140$ GeV, the missing momentum significance $\mathcal{S} > 8$, $\Delta\phi_{\min}(\vec{p}_{\text{T,1-4}},\vec{p}_{\text{T}}^{\text{miss}}) > 0.4$ and a lepton veto. The 'Orthogonalisation' selection is defined in the main body. In total 140000 raw MC events were generated prior to the specified cuts, with the column 'Unweighted yield' collecting the numbers after each cut.

Observed and expected upper limits at 95% CL on the production cross-section times branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 50 GeV

Observed and expected upper limits at 95% CL on the production cross-section times branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 60 GeV

Observed and expected upper limits at 95% CL on the production cross-section times branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 70 GeV

Observed 90% CL upper limits on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 20 GeV

Observed 90% CL upper limits on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 30 GeV

Observed 90% CL upper limits on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 40 GeV

Observed 90% CL upper limits on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 50 GeV

Observed 90% CL upper limits on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 60 GeV

Observed 90% CL upper limits on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 70 GeV

Observed 90% CL upper limits on $\epsilon^{2}$, assuming of $\alpha_{D}=0.1$, as a function of $m_{A'}$ at dark Higgs boson mass of 20 GeV

Observed 90% CL upper limits on $\epsilon^{2}$, assuming of $\alpha_{D}=0.1$, as a function of $m_{A'}$ at dark Higgs boson mass of 30 GeV

Observed 90% CL upper limits on $\epsilon^{2}$, assuming of $\alpha_{D}=0.1$, as a function of $m_{A'}$ at dark Higgs boson mass of 40 GeV

Observed 90% CL upper limits on $\epsilon^{2}$, assuming of $\alpha_{D}=0.1$, as a function of $m_{A'}$ at dark Higgs boson mass of 50 GeV

Observed 90% CL upper limits on $\epsilon^{2}$, assuming of $\alpha_{D}=0.1$, as a function of $m_{A'}$ at dark Higgs boson mass of 60 GeV

Observed 90% CL upper limits on $\epsilon^{2}$, assuming of $\alpha_{D}=0.1$, as a function of $m_{A'}$ at dark Higgs boson mass of 70 GeV

Observed and expected upper limits at 95% CL on the branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 20 GeV

Observed and expected upper limits at 95% CL on the branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 30 GeV

Observed and expected upper limits at 95% CL on the branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 40 GeV

Observed and expected upper limits at 95% CL on the branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 50 GeV

Observed and expected upper limits at 95% CL on the branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 60 GeV

Observed and expected upper limits at 95% CL on the branching fraction as a function of $m_{A'}$ at dark Higgs boson mass of 70 GeV

Observed and expected upper limits at 95% CL on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 20 GeV

Observed and expected upper limits at 95% CL on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 30 GeV

Observed and expected upper limits at 95% CL on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 40 GeV

Observed and expected upper limits at 95% CL on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 50 GeV

Observed and expected upper limits at 95% CL on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 60 GeV

Observed and expected upper limits at 95% CL on $\alpha_{D}\epsilon^{2}$ as a function of $m_{A'}$ at dark Higgs boson mass of 70 GeV

IRing2 for HT2>=500 GeV, NJets>=5

IRing2 for HT2>=1000 GeV, NJets>=2

IRing2 for HT2>=1000 GeV, NJets>=3

IRing2 for HT2>=1000 GeV, NJets>=4

IRing2 for HT2>=1000 GeV, NJets>=5

IRing2 for HT2>=1500 GeV, NJets>=2

IRing2 for HT2>=1500 GeV, NJets>=3

IRing2 for HT2>=1500 GeV, NJets>=4

IRing2 for HT2>=1500 GeV, NJets>=5

IRing128 for HT2>=500 GeV, NJets>=2

IRing128 for HT2>=500 GeV, NJets>=3

IRing128 for HT2>=500 GeV, NJets>=4

IRing128 for HT2>=500 GeV, NJets>=5

IRing128 for HT2>=1000 GeV, NJets>=2

IRing128 for HT2>=1000 GeV, NJets>=3

IRing128 for HT2>=1000 GeV, NJets>=4

IRing128 for HT2>=1000 GeV, NJets>=5

IRing128 for HT2>=1500 GeV, NJets>=2

IRing128 for HT2>=1500 GeV, NJets>=3

IRing128 for HT2>=1500 GeV, NJets>=4

IRing128 for HT2>=1500 GeV, NJets>=5

ICyl16 for HT2>=500 GeV, NJets>=2

ICyl16 for HT2>=500 GeV, NJets>=3

ICyl16 for HT2>=500 GeV, NJets>=4

ICyl16 for HT2>=500 GeV, NJets>=5

ICyl16 for HT2>=1000 GeV, NJets>=2

ICyl16 for HT2>=1000 GeV, NJets>=3

ICyl16 for HT2>=1000 GeV, NJets>=4

ICyl16 for HT2>=1000 GeV, NJets>=5

ICyl16 for HT2>=1500 GeV, NJets>=2

ICyl16 for HT2>=1500 GeV, NJets>=3

ICyl16 for HT2>=1500 GeV, NJets>=4

ICyl16 for HT2>=1500 GeV, NJets>=5

IRing2 covariance for HT2>=500 GeV, NJets>=2 (Table 1)

IRing2 covariance for HT2>=500 GeV, NJets>=3 (Table 2)

IRing2 covariance for HT2>=500 GeV, NJets>=4 (Table 3)

IRing2 covariance for HT2>=500 GeV, NJets>=5 (Table 4)

IRing2 covariance for HT2>=1000 GeV, NJets>=2 (Table 5)

IRing2 covariance for HT2>=1000 GeV, NJets>=3 (Table 6)

IRing2 covariance for HT2>=1000 GeV, NJets>=4 (Table 7)

IRing2 covariance for HT2>=1000 GeV, NJets>=5 (Table 8)

IRing2 covariance for HT2>=1500 GeV, NJets>=2 (Table 9)

IRing2 covariance for HT2>=1500 GeV, NJets>=3 (Table 10)

IRing2 covariance for HT2>=1500 GeV, NJets>=4 (Table 11)

IRing2 covariance for HT2>=1500 GeV, NJets>=5 (Table 12)

IRing128 covariance for HT2>=500 GeV, NJets>=2 (Table 13)

IRing128 covariance for HT2>=500 GeV, NJets>=3 (Table 14)

IRing128 covariance for HT2>=500 GeV, NJets>=4 (Table 15)

IRing128 covariance for HT2>=500 GeV, NJets>=5 (Table 16)

IRing128 covariance for HT2>=1000 GeV, NJets>=2 (Table 17)

IRing128 covariance for HT2>=1000 GeV, NJets>=3 (Table 18)

IRing128 covariance for HT2>=1000 GeV, NJets>=4 (Table 19)

IRing128 covariance for HT2>=1000 GeV, NJets>=5 (Table 20)

IRing128 covariance for HT2>=1500 GeV, NJets>=2 (Table 21)

IRing128 covariance for HT2>=1500 GeV, NJets>=3 (Table 22)

IRing128 covariance for HT2>=1500 GeV, NJets>=4 (Table 23)

IRing128 covariance for HT2>=1500 GeV, NJets>=5 (Table 24)

ICyl16 covariance for HT2>=500 GeV, NJets>=2 (Table 25)

ICyl16 covariance for HT2>=500 GeV, NJets>=3 (Table 26)

ICyl16 covariance for HT2>=500 GeV, NJets>=4 (Table 27)

ICyl16 covariance for HT2>=500 GeV, NJets>=5 (Table 28)

ICyl16 covariance for HT2>=1000 GeV, NJets>=2 (Table 29)

ICyl16 covariance for HT2>=1000 GeV, NJets>=3 (Table 30)

ICyl16 covariance for HT2>=1000 GeV, NJets>=4 (Table 31)

ICyl16 covariance for HT2>=1000 GeV, NJets>=5 (Table 32)

ICyl16 covariance for HT2>=1500 GeV, NJets>=2 (Table 33)

ICyl16 covariance for HT2>=1500 GeV, NJets>=3 (Table 34)

ICyl16 covariance for HT2>=1500 GeV, NJets>=4 (Table 35)

ICyl16 covariance for HT2>=1500 GeV, NJets>=5 (Table 36)

IRing2 covariance, complete

1-IRing128 covariance, complete

1-ICyl16 covariance, complete

Pre-fit comparison between data and background in the baseline SR for two of the variables used as input for the BSM pBDT: HT.

Data and post-fit background comparison for the distributions of the discriminant variables fitted in the control regions obtained with the background-only fit: CR HF e.

Data and post-fit background comparison for the distributions of the discriminant variables fitted in the control regions obtained with the background-only fit: CR HF mu.

Data and post-fit background comparison for the distributions of the discriminant variables fitted in the control regions obtained with the background-only fit: CR Conv.

Data and post-fit background comparison for the distributions of the discriminant variables fitted in the control regions obtained with the background-only fit: CR ttW.

Data and post-fit background comparison for the distributions of the discriminant variables fitted in the control regions obtained with the background-only fit: CR lowBDT.

Data and post-fit background comparison obtained with the background-only fit in the validation region defined for ttW+jets events: number of jets.

Data and post-fit background comparison obtained with the background-only fit in the validation region defined for ttW+jets events: SM BDT.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 400 GeV.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 1000 GeV.

Observed (black solid line) and expected (black dashed line) 95% CL upper limits on the ttH/A cross-section times branching fraction of H/A->tt as a function of mH/A.

Observed (red line) and expected (black dashed line) exclusion regions at 95% CL in the tan(beta) versus mass plane assuming that both, a heavy scalar H and pseudo-scalar A, contribute to the tttt final state and have the same mass mH=mA.

Observed (red line) and expected (black dashed line) exclusion regions at 95% CL in the tan(beta) versus mass plane assuming that only the scalar H contributes to the tttt final state.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 500 GeV.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 600 GeV.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 700 GeV.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 800 GeV.

Data and post-fit background comparison obtained with the background-only fit to the BSM SR for the BSM pBDT distribution used for mH = 900 GeV.

Observed (red line) and expected (black dashed line) exclusion regions at 95% CL in the tan(beta) versus mass plane assuming that only the pseudo-scalar A contributes to the tttt final state.

The product of acceptance and efficiency (A×ε), defined as the number of signal events satisfying the full set of selection criteria of the BSM SR, divided by the total number of generated signal events, for the tt̄H(→ tt̄ ) process in a type-II 2HDM for tanβ = 1 for the different heavy Higgs mass hypotheses.