Measurement of the inclusive and differential $\mathrm{t}\bar{\mathrm{t}}\gamma$ cross sections in the dilepton channel and effective field theory interpretation in proton-proton collisions at $\sqrt{s}=$ 13 TeV

Abstract

The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions in the decay channel with two oppositely charged leptons (e${}^{\pm }{\mu }^{\mp }$, e${}^{+}$e${}^{-}$, or ${\mu }^{+}{\mu }^{-}$). The measurement is performed using 138 fb${}^{-1}$ of proton-proton collision data recorded by the CMS experiment at $\sqrt{s}=$ 13 TeV during the 2016-2018 data-taking period of the CERN LHC. A fiducial phase space is defined such that photons radiated by initial-state particles, top quarks, or any of their decay products are included. An inclusive cross section of 175.2 $\pm$ 2.5 (stat) $\pm$ 6.3 (syst) fb is measured in a signal region with at least one jet coming from the hadronization of a bottom quark and exactly one photon with transverse momentum above 20 GeV. Differential cross sections are measured as functions of several kinematic observables of the photon, leptons, and jets, and compared to standard model predictions. The measurements are also interpreted in the standard model effective field theory framework, and limits are found on the relevant Wilson coefficients from these results alone and in combination with a previous CMS measurement of the $\mathrm{t}\bar{\mathrm{t}}\gamma$ production process using the lepton+jets final state.

Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-21-004 (CMS Public Pages)

References in corpus (17)

• 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
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions
• Tuning PYTHIA 8.1: the Monash 2013 Tune
• Single-top Wt-channel production matched with parton showers using the POWHEG method
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• The Catchment Area of Jets
• MCFM for the Tevatron and the LHC
• HATHOR for single top-quark production: Updated predictions and uncertainty estimates for single top-quark production in hadronic collisions
• Higgs boson production in association with top quarks in the POWHEG BOX
• A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector
• Effective-Field-Theory Approach to Top-Quark Production and Decay
• Effects of color reconnection on $t\bar{t}$ final states at the LHC
• Automated EW corrections with isolated photons: $t\bar{t}\gamma$, $t\bar{t}\gamma \gamma$ and $t\gamma j$ as case studies
• Electroweak corrections to top quark pair production in association with a hard photon at hadron colliders
• The top quark charge asymmetry in $t\bar{t}\gamma$ production at the LHC