Search

Abstract: This thesis presents results of a search for the neutral Higgs bosons (A/H) of the Minimal Supersymmetric Standard Model (MSSM) performed using the data corresponding to an integrated luminosity of 3.21 fb$^{-1}$ from proton-proton collisions at the centre of mass energy $\sqrt{s}$ = 13 TeV recorded by the ATLAS detector at the LHC. Two primary MSSM neutral Higgs production modes, gluon-gluon fusion and in association with b-quarks, are considered. The analysis presented here searches for events where the neutral Higgs bosons decay to a $\tau^+\tau^-$ pair with one $\tau$ decaying to leptons ($e/\mu$) and the other $\tau$ decaying to hadrons. The data are in good agreement with the background predicted by the Standard Model and the results provide an upper limit on the production cross section times branching fraction of the scalar boson decay to $\tau^+\tau^-$ as a function of the boson mass. The results are also interpreted in the $m_h^{mod+}$ MSSM benchmark scenario to derive exclusion limits on the $m_{A/H}-\tan\beta$ plane.