Measurements of inclusive and differential cross-sections of $t\bar{t}\gamma$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Abstract

Inclusive and differential cross-sections are measured at particle level for the associated production of a top quark pair and a photon ($t\bar{t}\gamma$). The analysis is performed using an integrated luminosity of 140 fb${}^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector. The measurements are performed in the single-lepton and dilepton top quark pair decay channels focusing on $t\bar{t}\gamma$ topologies where the photon is radiated from an initial-state parton or one of the top quarks. The absolute and normalised differential cross-sections are measured for several variables characterising the photon, lepton and jet kinematics as well as the angular separation between those objects. The observables are found to be in good agreement with the Monte Carlo predictions. The photon transverse momentum differential distribution is used to set limits on effective field theory parameters related to the electroweak dipole moments of the top quark. The combined limits using the photon and the $Z$ boson transverse momentum measured in $t\bar{t}$ production in associations with a $Z$ boson are also set.

arXiv comment76 pages in total, author list starting page 59, 25 figures, 9 tables, published in JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2018-24

References in corpus (34)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The anti-k_t jet clustering algorithm
• A Brief Introduction to PYTHIA 8.1
• FastJet user manual
• New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
• 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
• Herwig++ Physics and Manual
• PDF4LHC recommendations for LHC Run II
• Top++: a program for the calculation of the top-pair cross-section at hadron colliders
• Herwig 7.0 / Herwig++ 3.0 Release Note
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• An update on vector boson pair production at hadron colliders
• Event Generation with Sherpa 2.2
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• QCD matrix elements and truncated showers
• Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations
• Single-top hadroproduction in association with a W boson
• The Catchment Area of Jets
• Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production
• NNLL resummation for s-channel single top quark production
• Isolated photons in perturbative QCD
• Angular correlations of lepton pairs from vector boson and top quark decays in Monte Carlo simulations
• Operation of the ATLAS trigger system in Run 2
• Probing Electroweak Top Quark Couplings at Hadron Colliders
• SMEFTsim 3.0 -- a practical guide
• Pinning down electroweak dipole operators of the top quark
• EFTfitter---A tool for interpreting measurements in the context of effective field theories
• Electromagnetic dipole moments of the top quark
• Hard Photons in Hadroproduction of Top Quarks with Realistic Final States
• Off-shell vs on-shell modelling of top quarks in photon associated production

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• Observation of $W^{+}{W}^{-}\gamma$ production in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector and constraints on anomalous quartic gauge-boson couplings
• Probing top-quark electroweak couplings indirectly at the Electron-Ion Collider
• ATLAS EFT Results in the Top Quark Sector
• Measurements of inclusive and differential cross-sections of $t\bar{t}\gamma$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Photon production in top quark events at ATLAS and CMS