Charged Higgs bosons produced either in top-quark decays or in association with a top-quark, subsequently decaying via H ± → τ ± ν τ , are searched for in 36.1 fb −1 of proton-proton collision data at s=13 TeV recorded with the ATLAS detector. Depending on whether the top-quark produced together with H ± decays hadronically or leptonically, the search targets τ+jets and τ+lepton final states, in both cases with a hadronically decaying τ-lepton. No evidence of a charged Higgs boson is found. For the mass range of mH± = 90–2000 GeV, upper limits at the 95% confidence level are set on the production cross-section of the charged Higgs boson times the branching fraction ℬ (H ± → τ ± ν τ ) in the range 4.2–0.0025 pb. In the mass range 90–160 GeV, assuming the Standard Model cross-section for tt¯ production, this corresponds to upper limits between 0.25% and 0.031% for the branching fraction ℬ(t→bH±)×ℬ(H±→τ±ντ).[Figure not available: see fulltext.]

Aaboud, M., Aad, G., Abbott, B., Abdinov, O., Abeloos, B., Abhayasinghe, D.K., et al. (2018). Search for charged Higgs bosons decaying via H ± → τ ± ν τ in the τ+jets and τ+lepton final states with 36 fb −1 of pp collision data recorded at √s=13 TeV with the ATLAS experiment. JOURNAL OF HIGH ENERGY PHYSICS, 2018(9) [10.1007/JHEP09(2018)139].

Search for charged Higgs bosons decaying via H ± → τ ± ν τ in the τ+jets and τ+lepton final states with 36 fb −1 of pp collision data recorded at √s=13 TeV with the ATLAS experiment

Ceradini, F.;Di Micco, B.;Di Nardo, R.;