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. / The ATLAS Collaboration.

In: European Physical Journal C: Particles and Fields, Vol. 76, 658, 12.2016, p. 1-25.

Research output: Contribution to journalArticle



  • The ATLAS Collaboration


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.
Original languageEnglish
Article number658
Pages (from-to)1-25
Number of pages25
JournalEuropean Physical Journal C: Particles and Fields
Early online date29 Nov 2016
Publication statusPublished - Dec 2016
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

ID: 27613748