Measurements of the production cross-sections of the Standard Model (SM) Higgs boson (H) decaying into a pair of τ-leptons are presented. The measurements use data collected with the ATLAS detector from pp collisions produced at the Large Hadron Collider at a centre-of-mass energy of s√ = 13 TeV, corresponding to an integrated luminosity of 139 fb−1. Leptonic (τ → ℓνℓντ) and hadronic (τ → hadrons ντ) decays of the τ-lepton are considered. All measurements account for the branching ratio of H → ττ and are performed with a requirement |yH| < 2.5, where yH is the true Higgs boson rapidity. The cross-section of the pp → H → ττ process is measured to be 2.94 ± 0.21(stat)+0.37−0.32(syst) pb, in agreement with the SM prediction of 3.17 ± 0.09 pb. Inclusive cross-sections are determined separately for the four dominant production modes: 2.65 ± 0.41(stat)+0.91−0.67(syst) pb for gluon-gluon fusion, 0.197 ± 0.028(stat)+0.032−0.026(syst) pb for vector-boson fusion, 0.115 ± 0.058(stat)+0.042−0.040(syst) pb for vector-boson associated production, and 0.033 ± 0.031(stat)+0.022−0.017(syst) pb for top-quark pair associated production. Measurements in exclusive regions of the phase space, using the simplified template cross-section framework, are also performed. All results are in agreement with the SM predictions.
87 pages in total, author list starting page 65, 44 figures, 15 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2019-09/. The results including the correlation matrix are available at https://www.hepdata.net/record/115994