Search for heavy neutral MSSM Higgs bosons in the di-tau final state with the ATLAS detector

A search for heavy neutral Minimal Supersymmetric Standard Model Higgs bosons, $\mathcal{CP}$-even $H$ and $\mathcal{CP}$-odd $A$, is presented. The analysis uses $36.1\,{\rm fb^{-1}}$ data set collected in 2015 and 2016 with the ATLAS detector during Run 2 of the LHC at $\sqrt{s}=13\,{\rm TeV}$. Higgs bosons were searched for in the decay channel to a pair of tau leptons where one tau decays leptonically and another tau decays hadronically. No significant excess of events above the expected background from Standard Model processes was observed. Upper limits on cross section times branching ratio is set at a $95\%$ Confidence Level for two production modes of the Higgs bosons: gluon-gluon fusion and $b$-associated production. The results are also interpreted in $m_{\rm h}^{\rm mod-}$ and hMSSM benchmark scenarios of the MSSM. The analysis takes advantage of Higgs boson to down-type fermion coupling enhancement at high values of the $\tan\beta$ parameter of the MSSM and therefore is capable of excluding high $\tan\beta$ region in the $M_A-\tan\beta$ parameter space.