The ATLAS collaboration published the results of searching for the associative production of a Higgs boson and a top–antitop quark pair. Investigations were performed using the data collected in the channels of the Higgs boson decay into \(b\bar b\), WW∗, τ+τ−, γγ and ZZ∗over the entire LHC operation period. The production was observed with the statistical significance of 6.3 standard deviations at the expectation of 5.1 within the Standard Model. It is a pleasure to point out that DLNP scientists take an active part in this analysis, dealing with the channel of the Higgs boson decay into τ+τ−.
Measured total tt̄H production cross sections at 13 TeV, as well as observed (Obs.) and expected (Exp.) significances (sign.) relative to the background-only hypothesis. The results of the individual analyses, as well as the combined results are shown. Since no event is observed in the H → ZZ* → 4ℓ decay channel, an observed upper limit is set at 68% confidence level on the tt̄H production cross section in that channel using pseudo-experiments.