Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

Abstract

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139 fb${}^{-1}$ of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688 $\pm$ 23 (stat.) ${}_{-71}^{+75}$ (syst.) fb, to be compared with the standard model prediction of 515 ${}_{-42}^{+36}$ fb at next-to-leading order in QCD.

arXiv comment33 pages in total, author list starting page 18, 5 figures, 0 tables, published in Phys. Rev. Lett. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2018-44/

References in corpus (80)

• 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
• Asymptotic formulae for likelihood-based tests of new physics
• 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
• Parton distributions with LHC data
• The ATLAS Simulation Infrastructure
• PDF4LHC recommendations for LHC Run II
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• Scattering Amplitudes with Open Loops
• 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
• QCD Matrix Elements + Parton Showers
• Comix, a new matrix element generator
• Event Generation with Sherpa 2.2
• QCD matrix elements + parton showers: The NLO case
• High-precision QCD at hadron colliders: electroweak gauge boson rapidity distributions at NNLO
• Performance of the ATLAS Trigger System in 2015
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• QCD matrix elements and truncated showers
• Collier: a fortran-based Complex One-Loop LIbrary in Extended Regularizations
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations
• Single-top hadroproduction in association with a W boson
• Percent level precision physics at the Tevatron: first genuine NNLO QCD corrections to q qbar -> t tbar + X
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• Muon reconstruction performance of the ATLAS detector in proton--proton collision data at $\sqrt{s}$=13 TeV
• NNLO corrections to top-pair production at hadron colliders: the all-fermionic scattering channels
• NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction
• A critical appraisal of NLO+PS matching methods
• OpenLoops 2
• Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production
• The CT10 NNLO Global Analysis of QCD
• NNLL resummation for s-channel single top quark production
• Performance of pile-up mitigation techniques for jets in $pp$ collisions at $\sqrt{s}=8$ TeV using the ATLAS detector
• Uncertainties on alpha_S in global PDF analyses and implications for predicted hadronic cross sections
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• Hadronic top-quark pair production with NNLL threshold resummation
• Isolated photons in perturbative QCD
• ATLAS $b$-jet identification performance and efficiency measurement with $t\bar{t}$ events in $pp$ collisions at $\sqrt{s}=13$ TeV
• Jet energy scale measurements and their systematic uncertainties in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• HATHOR for single top-quark production: Updated predictions and uncertainty estimates for single top-quark production in hadronic collisions
• Performance of electron and photon triggers in ATLAS during LHC Run 2
• Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• 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
• Performance of the ATLAS muon triggers in Run 2
• Single-top t-channel hadroproduction in the four-flavour scheme with POWHEG and aMC@NLO
• Observation of $\mathrm{t}\overline{\mathrm{t}}$H production
• Electron reconstruction and identification in the ATLAS experiment using the 2015 and 2016 LHC proton-proton collision data at $\sqrt{s}$ = 13 TeV
• A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector
• O new physics, where art thou? A global search in the top sector
• On-the-fly reduction of open loops
• Observation of the associated production of a single top quark and a W boson in pp collisions at sqrt(s) = 8 TeV
• ATLAS flavour-tagging algorithms for the LHC Run 2 $pp$ collision dataset
• Constraining top quark effective theory in the LHC Run II era
• QCD corrections to top quark pair production in association with a photon at hadron colliders
• Measurement of the photon identification efficiencies with the ATLAS detector using LHC Run 2 data collected in 2015 and 2016
• Measurement of the $c$-jet mistagging efficiency in $t\bar{t}$ events using $pp$ collision data at $\sqrt{s}=13$ TeV collected with the ATLAS detector
• Measurement of the $t\bar{t}Z$ and $t\bar{t}W$ cross sections in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Measurement of the cross section for top quark pair production in association with a W or Z boson in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Calibration of the light-flavour jet mistagging efficiency of the $b$-tagging algorithms with $Z$+jets events using 139 ${\mathrm{fb}}^{-1}$ of ATLAS proton-proton collision data at $\sqrt{s}=13$ TeV
• The electro-weak couplings of the top and bottom quarks -- global fit and future prospects
• Observation of top-quark pair production in association with a photon and measurement of the $t\bar{t}\gamma$ production cross section in pp collisions at $\sqrt{s}=7$ TeV using the ATLAS detector
• Measurement of the production cross-section of a single top quark in association with a $W$ boson at 8 TeV with the ATLAS experiment
• Measurements of inclusive and differential fiducial cross-sections of $t\bar{t}\gamma$ production in leptonic final states at $\sqrt{s}$ = 13 TeV in ATLAS
• Observation of the associated production of a top quark and a $Z$ boson in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Measuring anomalous WW$\gamma$ and t$\bar{\text{t}}\gamma$ couplings using top+$\gamma$ production at the LHC
• Observation of single top quark production in association with a Z boson in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Automated EW corrections with isolated photons: $t\bar{t}\gamma$, $t\bar{t}\gamma \gamma$ and $t\gamma j$ as case studies
• Probing top quark electromagnetic dipole moments in single-top-plus-photon production
• Evidence for the associated production of a single top quark and a photon in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at $\sqrt{s}=13$ TeV
• QCD corrections in $tq\gamma$ production at hadron colliders

Cited by in corpus (4)

• Search for flavor changing neutral current interactions of the top quark in final states with a photon and additional jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for pair production of heavy resonances in final states with a photon and large-radius jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Towards a test of the Born rule in high-energy collisions
• Photon production in top quark events at ATLAS and CMS