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

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 ${\varphi }_{\tau }$ in the generalised Yukawa interaction. Without assuming the Standard Model hypothesis for the $H\to \tau \tau$ signal strength, the mixing angle ${\varphi }_{\tau }$ 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.

arXiv comment29 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/

References in corpus (60)

• The anti-k_t jet clustering algorithm
• An Introduction to PYTHIA 8.2
• FastJet user manual
• A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
• A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Parton distributions for the LHC Run II
• The ATLAS Simulation Infrastructure
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC $pp$ collision data at $\sqrt{s}=$ 7 and 8 TeV
• Event Generation with Sherpa 2.2
• Performance of the ATLAS Trigger System in 2015
• Production and Integration of the ATLAS Insertable B-Layer
• Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1
• Performance of pile-up mitigation techniques for jets in $pp$ collisions at $\sqrt{s}=8$ TeV using the ATLAS detector
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• Jet reconstruction and performance using particle flow with the ATLAS Detector
• Performance of electron and photon triggers in ATLAS during LHC Run 2
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• ATLAS data quality operations and performance for 2015-2018 data-taking
• Performance of missing transverse momentum reconstruction with the ATLAS detector using proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Jet energy scale and resolution measured in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• NNLOPS simulation of Higgs boson production
• Performance of the ATLAS muon triggers in Run 2
• Evidence for the 125 GeV Higgs boson decaying to a pair of tau leptons
• Higgs boson production in association with top quarks in the POWHEG BOX
• Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
• Measurements of Higgs boson properties in the diphoton decay channel with 36 fb${}^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV with the ATLAS detector
• Effective-Field-Theory Approach to Top-Quark Production and Decay
• A New Mass Reconstruction Technique for Resonances Decaying to di-tau
• Universal Interface of TAUOLA Technical and Physics Documentation
• Measurements of the Higgs boson width and anomalous HVV couplings from on-shell and off-shell production in the four-lepton final state
• Cross-section measurements of the Higgs boson decaying into a pair of tau-leptons in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Prospects of Measuring the Parity of Higgs Particles
• Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton-proton collisions at the LHC
• Measurement of the Higgs boson coupling properties in the $H\to Z{Z}^{\ast }\to 4\ell$ decay channel at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• $CP$ Properties of Higgs Boson Interactions with Top Quarks in the $t\bar{t}H$ and $tH$ Processes Using $H\to \gamma \gamma$ with the ATLAS Detector
• Measurements of $\mathrm{t}\bar{\mathrm{t}}$H production and the CP structure of the Yukawa interaction between the Higgs boson and the top quark in the diphoton decay channel
• Determining the CP parity of Higgs bosons at the LHC in their tau decay channels
• 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
• How to pin down the CP quantum numbers of a Higgs boson in its tau decays at the LHC
• Reconstruction of hadronic decay products of tau leptons with the ATLAS experiment
• Determining the CP parity of Higgs bosons at the LHC in the $\tau$ to 1-prong decay channels
• Measuring the Higgs boson's parity using tau --> rho nu
• Combined search for anomalous pseudoscalar HVV couplings in VH production and H to VV decay
• Probing the CP nature of the Higgs boson at linear colliders with tau spin correlations; the case of mixed scalar--pseudoscalar couplings
• Identification and rejection of pile-up jets at high pseudorapidity with the ATLAS detector
• Higgs CP properties using the tau decay modes at the ILC
• Prospects of constraining the Higgs CP nature in the tau decay channel at the LHC
• Determination of the Higgs CP mixing angle in the tau decay channels at the LHC including the Drell-Yan background
• Constraints on anomalous HVV couplings from the production of Higgs bosons decaying to $\tau$ lepton pairs
• The ATLAS Inner Detector Trigger performance in pp collisions at 13 TeV during LHC Run 2
• Analysis of the CP structure of the Yukawa coupling between the Higgs boson and $\tau$ leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Measurements of Higgs boson production cross-sections in the $H\to {\tau }^{+}{\tau }^{-}$ decay channel in $pp$ collisions at $\sqrt{s}=13\text{TeV}$ with the ATLAS detector
• TauSpinner program for studies on spin effect in tau production at the LHC
• Performance of the ATLAS Level-1 topological trigger in Run 2
• Potential for optimizing Higgs boson CP measurement in H to tau tau decay at LHC and ML techniques
• Documentation of TauSpinner algorithms -- program for simulating spin effects in tau-lepton production at LHC
• TauSpinner: a tool for simulating CP effects in H to tau tau decays at LHC
• Measurement of the energy response of the ATLAS calorimeter to charged pions from $W^{\pm }\to {\tau }^{\pm }(\to {\pi }^{\pm }{\nu }_{\tau }){\nu }_{\tau }$ events in Run 2 data

Cited by in corpus (6)

• Characterising the Higgs boson with ATLAS data from Run 2 of the LHC
• Accumulating Hints for Flavour Violating Higgses at the Electroweak Scale
• Search for pair production of boosted Higgs bosons via vector-boson fusion in the $b\bar{b}b\bar{b}$ final state using $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• A unified machine learning approach for reconstructing hadronically decaying tau leptons
• Ultimate Quantum Precision Limit at Colliders: Conditions and Case Studies
• Study $\gamma \gamma \to {\tau }^{+}{\tau }^{-}$ process including ${\tau }^{+}{\tau }^{-}$ spin information in Pb-Pb ultraperipheral collision and at Lepton collider