Projection of the Run 2 MSSM $\text{H} \to \tau\tau$ limits for the High-Luminosity LHC

A search for heavy Higgs bosons decaying to $\tau$ leptons was previously performed using data collected during Run 2 of the LHC, based on a data set of proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ corresponding to an integrated luminosity of $35.9~\mathrm{fb}^{-1}$. A projection of these results to a High-Luminosity LHC data set of $3000~\mathrm{fb}^{-1}$ is described. For neutral Higgs boson masses above $1~\mathrm{TeV}$, an improvement by about one order of magnitude is expected in the $95\%$ confidence level upper limits on the cross section. For the benchmark scenario $m_{\text{h}}^{\text{mod+}}$ of the minimal supersymmetric extension of the standard model, the expected lower limit on the mass of a heavy Higgs boson is extended from $1.25$ to $2~\mathrm{TeV}$ for $\tan \beta = 36$.