Measurement of the $CP$ properties of Higgs boson interactions with $\tau$-leptons with the ATLAS detector

ATLAS Collaboration

Preprint

PUBDB-2022-07951

Measurement of the $CP$ properties of Higgs boson interactions with $\tau$-leptons with the ATLAS detector

ATLAS Collaboration (Collaboration author)DESY*

2022

[10.3204/PUBDB-2022-07951]

This record in other databases:

Please use a persistent id in citations: doi:10.3204/PUBDB-2022-07951

Report No.: CERN-EP-2022-244; arXiv:2212.05833

Abstract: A study of the charge conjugation and parity ($CP$) properties of the interaction between the Higgs boson and $\tau$-leptons is presented. The study is based on a measurement of $CP$-sensitive angular observables defined by the visible decay products of $\tau$-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 $\sqrt{s}= 13$ TeV with the ATLAS detector at the Large Hadron Collider. Contributions from $CP$-violating interactions between the Higgs boson and $\tau$-leptons are described by a single mixing angle parameter $\phi_{\tau}$ in the generalised Yukawa interaction. Without assuming the Standard Model hypothesis for the $H\rightarrow\tau\tau$ signal strength, the mixing angle $\phi_{\tau}$ is measured to be $9^{\circ} \pm 16^{\circ}$, with an expected value of $0^{\circ} \pm 28^{\circ}$ 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.

Keyword(s): Higgs particle, interaction ; interaction, Yukawa ; ATLAS ; mixing angle ; parity ; charge conjugation ; hadronic decay ; CERN LHC Coll ; TeV

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/

Contributing Institute(s):