Abstract
A study of the charge conjugation and parity (CP) properties of the interaction between the Higgs boson and τ-leptons is presented. The study is based on a measurement of CP-sensitive angular observables defined by the visible decay products of τ-lepton decays, where at least one hadronic decay is required. The analysis uses 139 fb−1 of proton−proton collision data recorded at a centre-of-mass energy of √s = 13 TeV with the ATLAS detector at the Large Hadron Collider. Contributions from CP-violating interactions between the Higgs boson and τ-leptons are described by a single mixing angle parameter ϕτ in the generalised Yukawa interaction. Without assuming the Standard Model hypothesis for the H→ττ signal strength, the mixing angle ϕτ is measured to be 9∘±16∘, with an expected value of 0∘±28∘ at the 68% confidence level. The pure CP-odd hypothesis is disfavoured at a level of 3.4 standard deviations. The results are compatible with the predictions for the Higgs boson in the Standard Model.
Original language | English |
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Article number | 563 |
Number of pages | 30 |
Journal | European Physical Journal C |
Volume | 83 |
DOIs | |
Publication status | Published - 4 Jul 2023 |
Bibliographical note
29 pages in total, 9 figures, 7 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2019-10/
Keywords
- hep-ex