CERN Accelerating science

The distributions of leading and subleading (upper) muon $\pt$ and (lower) \PQb jet $\pt$ in the selected events. The uncertainty band in the lower panel represents the limited size of the simulated samples together with a 30\% uncertainty in the low-mass DY cross section. Simulated samples are normalized using the corresponding theoretical cross sections. To evaluate the normalization of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb = 2$.

The distributions of leading and subleading (upper) muon $\pt$ and (lower) \PQb jet $\pt$ in the selected events. The uncertainty band in the lower panel represents the limited size of the simulated samples together with a 30\% uncertainty in the low-mass DY cross section. Simulated samples are normalized using the corresponding theoretical cross sections. To evaluate the normalization of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb = 2$.

The distributions of leading and subleading (upper) muon $\pt$ and (lower) \PQb jet $\pt$ in the selected events. The uncertainty band in the lower panel represents the limited size of the simulated samples together with a 30\% uncertainty in the low-mass DY cross section. Simulated samples are normalized using the corresponding theoretical cross sections. To evaluate the normalization of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb = 2$.

The distributions of leading and subleading (upper) muon $\pt$ and (lower) \PQb jet $\pt$ in the selected events. The uncertainty band in the lower panel represents the limited size of the simulated samples together with a 30\% uncertainty in the low-mass DY cross section. Simulated samples are normalized using the corresponding theoretical cross sections. To evaluate the normalization of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb = 2$.

The \pt distributions of the (\cmsLeft) dimuon systems and (\cmsRight) di-\PQb-jet system. The uncertainty band in the lower panel represents the limited size of the simulated samples together with a 30\% uncertainty in the low-mass DY cross section. Simulated samples are normalized to using the corresponding theoretical cross sections. To evaluate the normalization of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb = 2$.

The \pt distributions of the (\cmsLeft) dimuon systems and (\cmsRight) di-\PQb-jet system. The uncertainty band in the lower panel represents the limited size of the simulated samples together with a 30\% uncertainty in the low-mass DY cross section. Simulated samples are normalized to using the corresponding theoretical cross sections. To evaluate the normalization of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb = 2$.

The distribution of \chib versus \chih as defined in Eq.~(\ref{eq:chil}) for (\cmsLeft) simulated background processes and (\cmsRight) the signal process with $\ma = 40\GeV$. The contours indicate lines of constant $\chit^2$. The gray scale represents the expected yields in data. To evaluate the yield of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb=2$.

The distribution of \chib versus \chih as defined in Eq.~(\ref{eq:chil}) for (\cmsLeft) simulated background processes and (\cmsRight) the signal process with $\ma = 40\GeV$. The contours indicate lines of constant $\chit^2$. The gray scale represents the expected yields in data. To evaluate the yield of the signal, SM Higgs boson cross sections are multiplied by the $\mathcal{B}(\ab\ab\to\mmbb)$ value that is calculated in the Type III model with $\tanb=2$.

Signal ($\ma=40\GeV$) versus background efficiency for different thresholds on $\chit^2$ (gray) and $\chid^2$ (red) variables. The black star indicates signal efficiency versus that of background for the optimized $\chid^2$ requirement.

Pre-fit distributions of the DNN score for the \mutau channel divided into events with one (\cmsLeft) or at least two (\cmsRight) \PQb jets. The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%. The lower panel shows the ratio of the observed data to the expected yields. The gray band represents the unconstrained statistical and systematic uncertainties.

Pre-fit distributions of the DNN score for the \mutau channel divided into events with one (\cmsLeft) or at least two (\cmsRight) \PQb jets. The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%. The lower panel shows the ratio of the observed data to the expected yields. The gray band represents the unconstrained statistical and systematic uncertainties.

The best fit background models for the \mmbb channel together with a 68\% CL uncertainty band from the fit to the data under the background-only hypothesis for the (upper left) Low\,\pt category, (middle left) VBF category, (middle right) TL category, (lower left) TM category, and (lower right) TT category. For comparison, the signal-plus-background is shown for the (upper right) Low\,\pt category for a signal with $\ma = 40\GeV$. The expected signal yield is evaluated assuming the SM production of the Higgs boson and $\mathcal{B}(\ab\ab\to\mmbb)=0.2\%$, as predicted in the Type III 2HDM+S with $\tanb=2$. The bin widths depend on statistics, irrelevant for the final fit.

The best fit background models for the \mmbb channel together with a 68\% CL uncertainty band from the fit to the data under the background-only hypothesis for the (upper left) Low\,\pt category, (middle left) VBF category, (middle right) TL category, (lower left) TM category, and (lower right) TT category. For comparison, the signal-plus-background is shown for the (upper right) Low\,\pt category for a signal with $\ma = 40\GeV$. The expected signal yield is evaluated assuming the SM production of the Higgs boson and $\mathcal{B}(\ab\ab\to\mmbb)=0.2\%$, as predicted in the Type III 2HDM+S with $\tanb=2$. The bin widths depend on statistics, irrelevant for the final fit.

The best fit background models for the \mmbb channel together with a 68\% CL uncertainty band from the fit to the data under the background-only hypothesis for the (upper left) Low\,\pt category, (middle left) VBF category, (middle right) TL category, (lower left) TM category, and (lower right) TT category. For comparison, the signal-plus-background is shown for the (upper right) Low\,\pt category for a signal with $\ma = 40\GeV$. The expected signal yield is evaluated assuming the SM production of the Higgs boson and $\mathcal{B}(\ab\ab\to\mmbb)=0.2\%$, as predicted in the Type III 2HDM+S with $\tanb=2$. The bin widths depend on statistics, irrelevant for the final fit.

The best fit background models for the \mmbb channel together with a 68\% CL uncertainty band from the fit to the data under the background-only hypothesis for the (upper left) Low\,\pt category, (middle left) VBF category, (middle right) TL category, (lower left) TM category, and (lower right) TT category. For comparison, the signal-plus-background is shown for the (upper right) Low\,\pt category for a signal with $\ma = 40\GeV$. The expected signal yield is evaluated assuming the SM production of the Higgs boson and $\mathcal{B}(\ab\ab\to\mmbb)=0.2\%$, as predicted in the Type III 2HDM+S with $\tanb=2$. The bin widths depend on statistics, irrelevant for the final fit.

The best fit background models for the \mmbb channel together with a 68\% CL uncertainty band from the fit to the data under the background-only hypothesis for the (upper left) Low\,\pt category, (middle left) VBF category, (middle right) TL category, (lower left) TM category, and (lower right) TT category. For comparison, the signal-plus-background is shown for the (upper right) Low\,\pt category for a signal with $\ma = 40\GeV$. The expected signal yield is evaluated assuming the SM production of the Higgs boson and $\mathcal{B}(\ab\ab\to\mmbb)=0.2\%$, as predicted in the Type III 2HDM+S with $\tanb=2$. The bin widths depend on statistics, irrelevant for the final fit.

The best fit background models for the \mmbb channel together with a 68\% CL uncertainty band from the fit to the data under the background-only hypothesis for the (upper left) Low\,\pt category, (middle left) VBF category, (middle right) TL category, (lower left) TM category, and (lower right) TT category. For comparison, the signal-plus-background is shown for the (upper right) Low\,\pt category for a signal with $\ma = 40\GeV$. The expected signal yield is evaluated assuming the SM production of the Higgs boson and $\mathcal{B}(\ab\ab\to\mmbb)=0.2\%$, as predicted in the Type III 2HDM+S with $\tanb=2$. The bin widths depend on statistics, irrelevant for the final fit.

Post-fit distributions of \mtt for the \mutau channel signal regions in events with exactly one \PQb tagged jet: SR1 (\cmsULeft), SR2 (\cmsURight), and SR3 (lower). The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Post-fit distributions of \mtt for the \mutau channel signal regions in events with exactly one \PQb tagged jet: SR1 (\cmsULeft), SR2 (\cmsURight), and SR3 (lower). The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Post-fit distributions of \mtt for the \mutau channel signal regions in events with exactly one \PQb tagged jet: SR1 (\cmsULeft), SR2 (\cmsURight), and SR3 (lower). The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Post-fit distributions of the \mtt for the \mutau channel signal regions in events with at least two \PQb tagged jets: SR1 (\cmsLeft) and SR2 (\cmsRight). The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Post-fit distributions of the \mtt for the \mutau channel signal regions in events with at least two \PQb tagged jets: SR1 (\cmsLeft) and SR2 (\cmsRight). The shape of the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is indicated assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Post-fit distributions of the \mtt for the \mutau channel control regions in events with exactly one \PQb tagged jet (\cmsLeft) and at least two \PQb tagged jets (\cmsRight). The contamination from the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is barely visible assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Post-fit distributions of the \mtt for the \mutau channel control regions in events with exactly one \PQb tagged jet (\cmsLeft) and at least two \PQb tagged jets (\cmsRight). The contamination from the $\Hb\to\ab\ab$ signal, where $\ma = 35\GeV$, is barely visible assuming $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ to be 10\%.

Observed and expected upper limits at 95\% \CL on $\mathcal{B}(\Hb\to\ab\ab\to \mmbb)$ as functions of \ma. The inner and outer bands indicate the regions containing the distribution of limits located within 68 and 95\% confidence intervals, respectively, of the expectation under the background-only hypothesis.

Observed and expected 95\% \CL exclusion limits on $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ in percent, for the (upper left) \mutau, (upper right) \etau, (lower left) \emu channels, and (lower right) for the combination of all the channels.

Observed and expected 95\% \CL exclusion limits on $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ in percent, for the (upper left) \mutau, (upper right) \etau, (lower left) \emu channels, and (lower right) for the combination of all the channels.

Observed and expected 95\% \CL exclusion limits on $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ in percent, for the (upper left) \mutau, (upper right) \etau, (lower left) \emu channels, and (lower right) for the combination of all the channels.

Observed and expected 95\% \CL exclusion limits on $\mathcal{B}(\Hb\to\ab\ab\to\ttbb)$ in percent, for the (upper left) \mutau, (upper right) \etau, (lower left) \emu channels, and (lower right) for the combination of all the channels.

Observed and expected 95\% CL upper limits on $\mathcal{B}(\Hb\to\ab\ab\to \ell\ell\PQb\PQb)$ in \%, where $\ell$ stands for muons or \PGt leptons, obtained from the combination of the \mmbb and \ttbb channels. The results are obtained as functions of \ma for 2HDM+S models, independent of the type and $\tanb$ parameter.

Observed and expected 95\% CL upper limits on $\mathcal{B}(\Hb\to\ab\ab)$ in \%, obtained from the combination of the \mmbb and \ttbb channels. The results are obtained as functions of \ma for 2HDM+S Type I (independent of $\tanb$), Type II ($\tanb=2.0$), Type III ($\tanb=2.0$), and Type IV ($\tanb=0.6$), respectively.

Observed 95\% CL upper limits on $\mathcal{B}(\Hb\to\ab\ab)$ in \%, for the combination of the \mmbb and \ttbb channels for Type III (\cmsLeft) and Type IV (\cmsRight) 2HDM+S in the \tanb \vs \ma parameter space. The limits are calculated in a grid of 5\GeV in \ma and $0.1$--$0.5$ in \tanb, interpolating the points in between. The contours corresponding to branching fractions of 100 and 16\% are drawn using dashed lines, where 16\% refers to the combined upper limit on Higgs boson to undetected particle decays from previous Run~2 results~\cite{naturecombcms}. All points inside the contour are allowed within that upper limit.

Observed 95\% CL upper limits on $\mathcal{B}(\Hb\to\ab\ab)$ in \%, for the combination of the \mmbb and \ttbb channels for Type III (\cmsLeft) and Type IV (\cmsRight) 2HDM+S in the \tanb \vs \ma parameter space. The limits are calculated in a grid of 5\GeV in \ma and $0.1$--$0.5$ in \tanb, interpolating the points in between. The contours corresponding to branching fractions of 100 and 16\% are drawn using dashed lines, where 16\% refers to the combined upper limit on Higgs boson to undetected particle decays from previous Run~2 results~\cite{naturecombcms}. All points inside the contour are allowed within that upper limit.