Probing the Higgs boson CP properties in vector-boson fusion production in the H → τ + τ − channel with the ATLAS detector

Journal article

The CP properties of the Higgs boson are studied in the vector-boson fusion production mode. The analysis exploits the decay mode of the Higgs boson into two τ-leptons using 140 fb−1 of proton-proton collision data at s=13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Results are obtained using the Optimal Observable method. CP-violating interactions between the Higgs boson and electroweak gauge bosons are considered in the effective field theory framework, with the interaction strength described in the HISZ basis by d~, and in the Warsaw basis by cHW~, cHB~, and cHW~B. No deviations relative to the Standard Model are observed, and limits are obtained on the strength parameters. The d~ parameter is constrained to the interval [−0.012, 0.044] at the 95% confidence level while cHW~ is constrained to [−0.24, 0.83], when considering both linear and quadratic effects of physics beyond the Standard Model.

Authors: Aad, G; Aakvaag, E; Abbott, B; Abdelhameed, S; Abeling, K

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Journal of High Energy Physics
• Volume: 2025
• Issue: 10
• Article number: 92
• Publication date: 2025-10-10
• Acceptance date: 2025-09-12
• DOI: 10.1007/jhep10(2025)092
• EISSN: 1029-8479
• ISSN: 1126-6708
• Language: English
• Keywords: Hadron-Hadron Scattering