"Figure 8: 95% CL upper limit on XSEC times BR" of "Search for charged Higgs bosons decaying into top and bottom quarks at $\sqrt{s}$ = 13 TeV with the ATLAS detector"

CERN-LHC. A search for charged Higgs bosons heavier than the top quark and decaying via $H^\pm\to tb$ is presented. The dataset analysed corresponds to 36.1 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}=13$ TeV and was recorded with the ATLAS detector at the LHC in 2015 and 2016. The production of a charged Higgs boson in association with a top quark and a bottom quark, $pp \to tbH^\pm$, is explored in the mass range from $m_{H^\pm}=200$ to $2000$ GeV using multi-jet final states with one or two electrons or muons. Events are categorised according to the multiplicity of jets and how likely these are to have originated from hadronisation of a bottom quark. Multivariate techniques are used to discriminate between signal and background events. No significant excess above the background-only hypothesis is observed and exclusion limits are derived for the production cross-section times branching ratio of a charged Higgs boson as a function of its mass, which range from 2.9 pb at $m_{H^\pm} = 200$ GeV to 0.070 pb at $m_{H^\pm} = 2000$ GeV. The results are interpreted in two benchmark scenarios of the Minimal Supersymmetric Standard Model.

Expected and observed limits for the production of $H^{+} \to tb$ in association with a top quark and a bottom quark. The bands surrounding the expected limit show the 68% and 95% confidence intervals. The limits are based on the combination of the $\ell+$jets and $\ell\ell$ final states. Theory predictions are shown for three representative values of $\tan\beta$ in the $m_h^{\mathrm{mod-}}$ benchmark scenario. Uncertainties in the predicted $H^+$ cross-sections or branching ratios are not considered.