Test of CP invariance in vector-boson fusion production of the Higgs boson using the Optimal Observable method in the ditau decay channel with the ATLAS detector

Summary, in English

A test of CP invariance in Higgs boson production via vector-boson fusion using the method of the Optimal Observable is presented. The analysis exploits the decay mode of the Higgs boson into a pair of τ leptons and is based on 20.3 fb - 1 of proton–proton collision data at s = 8 TeV collected by the ATLAS experiment at the LHC. Contributions from CP-violating interactions between the Higgs boson and electroweak gauge bosons are described in an effective field theory framework, in which the strength of CP violation is governed by a single parameter d~. The mean values and distributions of CP-odd observables agree with the expectation in the Standard Model and show no sign of CP violation. The CP-mixing parameter d~ is constrained to the interval (- 0.11 , 0.05) at 68% confidence level, consistent with the Standard Model expectation of d~ = 0. © 2016, CERN for the benefit of the ATLAS collaboration.

• Author: G Aad; B. Abbott; O Abdinov; J Abdallah; B Abeloos; R Aben; Torsten Åkesson; Simona Bocchetta; LENE BRYNGEMARK; Caterina Doglioni; Anders Floderus; Anthony Hawkins; Vincent Hedberg; Jenny Ivarsson; Göran Jarlskog; Else Lytken; Ulf Mjörnmark; Oxana Smirnova; Oleksandr Viazlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2016
• Language: English
• Publication/Series: European Physical Journal C
• Volume: 76
• Issue: 12
• Links: http://dx.doi.org/10.1140/epjc/s10052-016-4499-5
• Document type: Journal article
• Publisher: Springer
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044