Search for additional heavy neutral Higgs and gauge bosons in the ditau final state produced in 36 fb−1 of pp collisions at √s = 13 TeV with the ATLAS detector

Abstract

A search for heavy neutral Higgs bosons and Z′ bosons is performed using a data sample corresponding to an integrated luminosity of 36.1fb−1 from proton–proton collisions at √s = 13 TeV recorded by the ATLAS detector at the LHC during 2015 and 2016. The heavy resonance is assumed to decay to τ+τ− with at least one tau lepton decaying to final states with hadrons and a neutrino. The search is performed in the mass range of 0.2–2.25 TeV forHiggsbosonsand0.2–4.0TeVforZ′ bosons. Thedataareingoodagreementwiththe background predicted by the Standard Model. The results are interpreted in benchmark scenarios. In the context of the hMSSM scenario, the data exclude tan β > 1.0 for mA = 0.25 TeV and tan β > 42 for mA = 1.5 TeV at the 95% confidence level. For the Sequential Stand- ard Model, Z′ with mZ′ < 2.42 TeV is excluded at 95% confidence level, while Z′ with SSM NU mZ′ <2.25TeVisexcludedforthenon-universalG(221)modelthatexhibitsenhancedcoup- lings to third-generation fermions.