Measurement of high-mass $t\bar{t}{\ell }^{+}{\ell }^{-}$ production and lepton flavour universality-inspired effective field theory interpretations at $\sqrt{s}=13$ TeV with the ATLAS detector

Abstract

Measurements of $t\bar{t}{\ell }^{+}{\ell }^{-}$ production in the region of high dilepton invariant mass with effective field theory (EFT) interpretations are presented. They are performed using final states with three isolated leptons (electrons or muons) and are based on $\sqrt{s}=13$ TeV proton-proton collision data with an integrated luminosity of $140{\mathrm{fb}}^{-1}$, recorded from 2015 to 2018 with the ATLAS detector at the Large Hadron Collider. Measurements of the $t\bar{t}{\ell }^{+}{\ell }^{-}$ signal strength and cross-section upper-limits are performed inclusively in lepton flavour and separately for electrons and muons. The study also aims to probe anomalous four-fermion interactions including to test for possible lepton flavor universality violation. No significant deviations from the Standard Model predictions are observed and the measurements are interpreted through the EFT formalism to provide new constraints on relevant operators.

53 pages in total, author list starting page 36, 9 figures, 10 tables, published by EPJC. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2023-02

References in corpus (33)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• Event generation with SHERPA 1.1
• Herwig++ Physics and Manual
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations
• The Catchment Area of Jets
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• Jet energy scale and resolution measured in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Performance of the ATLAS muon triggers in Run 2
• Measurement of the $\tau$ lepton polarization and $R(D^{\ast })$ in the decay $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$ with one-prong hadronic $\tau$ decays at Belle
• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• tWH associated production at the LHC
• SMEFTsim 3.0 -- a practical guide
• On the maximal use of Monte Carlo samples: re-weighting events at NLO accuracy
• Charm Physics Confronts High-$p_T$ Lepton Tails
• Measurement of the ratios of branching fractions $\mathcal{R}(D^{\ast })$ and $\mathcal{R}(D^0)$
• Test of lepton flavour universality using $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ decays with hadronic $\tau$ channels
• Top and Beauty synergies in SMEFT-fits at present and future colliders
• Observation of four-top-quark production in the multilepton final state with the ATLAS detector
• On improving NLO merging for $t\bar{t}W$ production
• Software and computing for Run 3 of the ATLAS experiment at the LHC
• Studies of the muon momentum calibration and performance of the ATLAS detector with $pp$ collisions at $\sqrt{s}$=13 TeV
• The ATLAS Inner Detector Trigger performance in pp collisions at 13 TeV during LHC Run 2
• More Synergies from Beauty, Top, $Z$ and Drell-Yan Measurements in SMEFT
• Electron and photon efficiencies in LHC Run 2 with the ATLAS experiment
• The performance of missing transverse momentum reconstruction and its significance with the ATLAS detector using 140 fb${}^{-1}$ of $\sqrt{s}=13$ TeV $pp$ collisions
• Electron and photon energy calibration with the ATLAS detector using LHC Run 2 data
• Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at $\sqrt{s}=$ 13 TeV
• Inclusive and differential cross-section measurements of $t\bar{t}Z$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector, including EFT and spin-correlation interpretations
• Measurement of the total and differential cross-sections of $t\bar{t}W$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Measurements of inclusive and differential cross sections for top quark production in association with a Z boson in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for physics beyond the standard model in top quark production with additional leptons in the context of effective field theory