Search for charged-lepton flavor violation in the production and decay of top quarks using trilepton final states in proton-proton collisions at $\sqrt{s}$ = 13 TeV

Abstract

A search is performed for charged-lepton flavor violating processes in top quark (t) production and decay. The data were collected by the CMS experiment from proton-proton collisions at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 138 fb${}^{-1}$. The selected events are required to contain one opposite-sign electron-muon pair, a third charged lepton (electron or muon), and at least one jet of which no more than one is associated with a bottom quark. Boosted decision trees are used to distinguish signal from background, exploiting differences in the kinematics of the final states particles. The data are consistent with the standard model expectation. Upper limits at 95% confidence level are placed in the context of effective field theory on the Wilson coefficients, which range between 0.024-0.424 TeV${}^{-2}$ depending on the flavor of the associated light quark and the Lorentz structure of the interaction. These limits are converted to upper limits on branching fractions involving up (charm) quarks, t $\to$ e$\mu$u (t $\to$ e$\mu$c), of 0.032 (0.498) $\times$ 10${}^{-6}$, 0.022 (0.369) $\times$ 10${}^{-6}$, and 0.012 (0.216) $\times$ 10${}^{-6}$ for tensor-like, vector-like, and scalar-like interactions, respectively.

arXiv commentReplaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-22-005 (CMS Public Pages)

References in corpus (47)

• 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
• An Introduction to PYTHIA 8.2
• Evidence for oscillation of atmospheric neutrinos
• FastJet user manual
• Asymptotic formulae for likelihood-based tests of new physics
• Direct Evidence for Neutrino Flavor Transformation from Neutral-Current Interactions in the Sudbury Neutrino Observatory
• 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
• Dimension-Six Terms in the Standard Model Lagrangian
• Confidence Level Computation for Combining Searches with Small Statistics
• Parton distributions from high-precision collider data
• PDF4LHC recommendations for LHC Run II
• Dispelling the N^3 myth for the Kt jet-finder
• Top++: a program for the calculation of the top-pair cross-section at hadron colliders
• Particle-flow reconstruction and global event description with the CMS detector
• Tuning PYTHIA 8.1: the Monash 2013 Tune
• Vector boson pair production at the LHC
• The CMS trigger system
• Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV
• Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV
• Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements
• Performance of the CMS Level-1 trigger in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Precision luminosity measurement in proton-proton collisions at $\sqrt{s}=$ 13 TeV in 2015 and 2016 at CMS
• Measurements of Inclusive W and Z Cross Sections in pp Collisions at sqrt(s)=7 TeV
• Electron and photon reconstruction and identification with the CMS experiment at the CERN LHC
• Performance of missing transverse momentum reconstruction in proton-proton collisions at $\sqrt{s}=$ 13 TeV using the CMS detector
• The SMEFTsim package, theory and tools
• Measurement of the inelastic proton-proton cross section at $\sqrt{s}=$ 13 TeV
• Jet Flavour Classification Using DeepJet
• Top-pair production and decay at NLO matched with parton showers
• 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
• Associated top quark pair production with a heavy boson: differential cross sections at NLO+NNLL accuracy
• Measurement of the ratios of branching fractions $\mathcal{R}(D^{\ast })$ and $\mathcal{R}(D^0)$
• On improving NLO merging for $t\bar{t}W$ production
• SmeftFR -- Feynman rules generator for the Standard Model Effective Field Theory
• Correlation between $R_{D^{(\ast )}}$ and top quark FCNC decays in leptoquark models
• LHC sensitivity to lepton flavour violating Z boson decays
• Observation of single top quark production in association with a Z boson in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Lepton Flavour Violating top decays at the LHC
• Inclusive and differential cross section measurements of single top quark production in association with a Z boson in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for charged-lepton flavor violation in top quark production and decay in pp collisions at $\sqrt{s}=$ 13 TeV
• Improving estimates of the number of fake leptons and other mis-reconstructed objects in hadron collider events: BoB's your UNCLE. (Previously "The Matrix Method Reloaded")
• Model-Independent Constraints on Lepton-Flavor-Violating Decays of the Top Quark

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