Search for minimal supersymmetric standard model Higgs Bosons H / A and for a Z^′ boson in the ττ final state produced in pp collisions at √s=13 TeV with the ATLAS detector

A search for neutral Higgs bosons of the minimal supersymmetric standard model (MSSM) and for a heavneutral Z^′ boson is performed using a data sample corresponding to an integrated luminosity of 3.2 fb^{- 1} from proton–proton collisions at s=13 TeV recorded by the ATLAS detector at the LHC. The heavy resonance is assumed to decay to a τ⁺τ^- pair with at least one τ lepton decaying to final states with hadrons and a neutrino. The search is performed in the mass range of 0.2–1.2 TeV for the MSSM neutral Higgs bosons and 0.5–2.5 TeV for the heavy neutral Z^′ boson. The data are in good agreement with the background predicted by the Standard Model. The results are interpreted in MSSM and Z^′ benchmark scenarios. The most stringent constraints on the MSSM m_A–tan β space exclude at 95 % confidence level (CL) tan β> 7.6 for m_A= 200 GeV in the mhmod+ MSSM scenario. For the Sequential Standard Model, a ZSSM′ mass up to 1.90 TeV is excluded at 95 % CL and masses up to 1.82–2.17 TeV are excluded for a ZSFM′ of the strong flavour model.