$CP$ 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

Abstract

A study of the $CP$ properties of the interaction between the Higgs boson and top quarks is presented. Higgs bosons are identified via the diphoton decay channel ($H\to \gamma \gamma$) and their production in association with a top quark pair ($t\bar{t}H$) or single top quark ($tH$) is studied. The analysis uses 139 fb${}^{-1}$ of proton-proton collision data recorded at a center-of-mass energy of $\sqrt{s}$ = 13 TeV with the ATLAS detector at the Large Hadron Collider. Assuming a $CP$-even coupling, the $t\bar{t}H$ process is observed with a significance of 5.2 standard deviations. The measured cross section times $H\to \gamma \gamma$ branching ratio is $1.64{}_{-0.36}^{+0.38}\text{(stat.)}{}_{-0.14}^{+0.17}(\text{sys.})$ fb, and the measured rate for $t\bar{t}H$ is $1.43{}_{-0.31}^{+0.33}\text{(stat.)}{}_{-0.15}^{+0.21}(\text{sys.})$ times the Standard Model expectation. The $tH$ production process is not observed and an upper limit on its rate of 12 times the Standard Model expectation is set. A $CP$-mixing angle greater (less) than 43 (-43)${}^{\circ }$ is excluded at 95% confidence level.

29 pages in total, author list starting page 13, 3 figures, no tables, published in Phys. Rev. Lett. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2019-01/

References in corpus (13)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Combined Measurement of the Higgs Boson Mass in $pp$ Collisions at $\sqrt{s}=7$ and 8 TeV with the ATLAS and CMS Experiments
• Higgs boson gluon-fusion production in N3LO QCD
• NLO Electroweak Corrections to Higgs Boson Production at Hadron Colliders
• Electroweak and QCD corrections to Higgs production via vector-boson fusion at the LHC
• Measurement of the $Z/{\gamma }^{\ast }$ boson transverse momentum distribution in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detector
• Strong and electroweak corrections to the production of Higgs+2jets via weak interactions at the LHC
• Precise predictions for the Higgs-boson decay H -> W W/Z Z -> 4 leptons
• Effective-Field-Theory Approach to Top-Quark Production and Decay
• QCD NLO and EW NLO corrections to $t\bar{t}H$ production with top quark decays at hadron collider
• Measurements of the Higgs boson width and anomalous HVV couplings from on-shell and off-shell production in the four-lepton final state
• Higgs characterisation at NLO in QCD: CP properties of the top-quark Yukawa interaction
• 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

Cited by in corpus (50)

• Collider Physics at the Precision Frontier
• 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
• Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at $\sqrt{s}=$ 13 TeV
• Measurement of the Higgs boson production rate in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at $\sqrt{s}=$ 13 TeV
• Constraints on anomalous Higgs boson couplings to vector bosons and fermions in its production and decay using the four-lepton final state
• Observation of four-top-quark production in the multilepton final state with the ATLAS detector
• Search for a heavy Higgs boson decaying into a $Z$ boson and another heavy Higgs boson in the $\ell \ell bb$ and $\ell \ell WW$ final states in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• SPANet: Generalized Permutationless Set Assignment for Particle Physics using Symmetry Preserving Attention
• Les Houches 2021: Physics at TeV Colliders: Report on the Standard Model Precision Wishlist
• Constraining the CP structure of Higgs-fermion couplings with a global LHC fit, the electron EDM and baryogenesis
• Permutationless Many-Jet Event Reconstruction with Symmetry Preserving Attention Networks
• Machine learning the Higgs boson-top quark CP phase
• Scrutinizing the 95-100 GeV di-tau excess in the top associated process
• Probing the CP structure of the top quark Yukawa coupling: Loop sensitivity vs. on-shell sensitivity
• Direct Higgs-top CP-phase measurement with $t\bar{t}h$ at the 14 TeV LHC and 100 TeV FCC
• ν-Flows: Conditional Neutrino Regression
• Measurements of Higgs boson production in the decay channel with a pair of $\tau$ leptons in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Production and decay of the Higgs boson in association with top quarks
• The Higgs boson -- its implications and prospects for future discoveries
• Returning CP-Observables to The Frames They Belong
• ATLAS Violating CP Effectively
• A Reduced basis for CP violation in SMEFT at colliders and its application to Diboson production
• Measurement of the $CP$ properties of Higgs boson interactions with $\tau$-leptons with the ATLAS detector
• Constraints on Higgs boson properties using $W{W}^{\ast }(\to e\nu \mu \nu )jj$ production in 36.1 fb${}^{-1}$ of $\sqrt{s}$=13 TeV $pp$ collisions with the ATLAS detector
• A Holistic Approach to Predicting Top Quark Kinematic Properties with the Covariant Particle Transformer
• Probing the electroweak symmetry breaking with Higgs production at the LHC
• Search for the non-resonant production of Higgs boson pairs via gluon fusion and vector-boson fusion in the $b\bar{b}{\tau }^{+}{\tau }^{-}$ final state in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Constraints on anomalous Higgs boson couplings to vector bosons and fermions from the production of Higgs bosons using the $\tau \tau$ final state
• P-even, CP-violating Signals in Scalar-Mediated Processes
• Search for new physics using effective field theory in 13 TeV pp collision events that contain a top quark pair and a boosted Z or Higgs boson
• Les Houches 2023 -- Physics at TeV Colliders: Report on the Standard Model Precision Wishlist
• Charged Higgs decay to $W^{\pm }H$ at a high energy lepton collider
• Test of $CP$ Invariance in Higgs Boson Vector-Boson-Fusion Production Using the $H\to \gamma \gamma$ Channel with the ATLAS Detector
• Single Top Quark Production with and without a Higgs Boson
• Study on the sensitivity of the Higgs boson couplings in photon-photon collision at CLIC and muon collider
• Parton Labeling without Matching: Unveiling Emergent Labelling Capabilities in Regression Models
• Influence of QCD parton shower in deep learning invisible Higgs through vector boson fusion
• Kinematic corrections and reconstruction methods for neutral Higgs boson decay to $b\bar{b}$ in 2HDM type-I at future lepton colliders
• H1jet, a fast program to compute transverse momentum distributions
• Heavy neutral 2HDM Higgs Boson Pair Production at CLIC Energies
• Probing CP-violating Higgs-gauge Boson Couplings at Future Muon Collider
• State-of-the-art cross sections for ttH: NNLO predictions matched with NNLL resummation and EW corrections
• Interpretation of LHC excesses at 95 GeV and 152 GeV in an extended Georgi-Machacek model
• Observability of 2HDM charged Higgs boson in a misaligned scenario
• Decay of the Higgs boson to longitudinally polarized leptons and quarks
• $t\bar{t}jj$ -- NLO QCD corrections to top quark pair production and decays at the LHC
• Combination of measurements of CP properties of Higgs boson interactions with vector bosons using proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Complete NLO corrections to $t\bar{t}\gamma$ and $t\bar{t}\gamma \gamma$
• Proposal for simplified template cross-sections extension using $\mathcal{C}\mathcal{P}$ observables in $t\overline{t}H$
• Illuminating all-hadronic final states with a photon: Exotic decays of the Higgs boson to four bottom quarks in vector boson fusion plus gamma at hadron colliders