Machine Learning Approaches to Top Quark Flavor-Changing Four-Fermion Interactions in Trilepton Signals at the LHC

Abstract

We explore the top quark flavor-changing 4-Fermi interactions ($tuee$ and $tcee$) with scalar, vector, and tensor structures using machine learning models to analyze tri-lepton processes at the LHC. The study is performed using $t\bar{t}$ and $tW$ processes, where a top quark decays into $u/c+e^{+}+e^{-}$. The analysis incorporates both reducible and irreducible backgrounds while accounting for realistic detector effects. The dominant backgrounds for these trilepton signatures arise from $t\bar{t}$ production, single top quark production in association with $V$, and $VV$ production (where $V=W,Z$). These backgrounds are significantly reduced using machine learning-based classification models, which optimize event selection and improve signal sensitivity. For an integrated luminosity of 3000 fb${}^{-1}$ at the LHC, we find that the expected $95\%$ confidence level (CL) limits on the scale of 4-Fermi FCNC interactions reach $\Lambda \le 5.5$ TeV for $tuee$ and $\Lambda \le 5.7$ TeV for $tcee$ in the $t\bar{t}$ channel, and $\Lambda \le 1.9$ TeV ($tuee$) and $\Lambda \le 2.0$ TeV ($tcee$) in the $tW$ channel. We also provide an interpretation of our EFT analysis in the context of a specific $Z^{\prime }$ model, illustrating how the derived constraints translate into bounds on the parameter space of a heavy neutral gauge boson mediating flavor-changing interactions.

20 pages, 11 figures

References in corpus (49)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The anti-k_t jet clustering algorithm
• FastJet user manual
• DELPHES 3, A modular framework for fast simulation of a generic collider experiment
• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• MadGraph 5 : Going Beyond
• Dispelling the N^3 myth for the Kt jet-finder
• UFO - The Universal FeynRules Output
• A minimal set of top anomalous couplings
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2021
• The RooFit toolkit for data modeling
• A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector
• Compilation of low-energy constraints on 4-fermion operators in the SMEFT
• A global approach to top-quark flavor-changing interactions
• Effective four-fermion operators in top physics: a roadmap
• Charm Meson Decays
• $D^0-\overline{D^0}$ Mixing and Rare Charm Decays
• Probing top flavour-changing neutral scalar couplings at the CERN LHC
• Search for Single Top Production at LEP
• Deciphering top flavor violation at the LHC with B factories
• $t\to cV$ via SUSY FCNC couplings in the unconstrained MSSM
• Semitauonic $b$-hadron decays: A lepton flavor universality laboratory
• Single Top-Quark Production in Flavor-Changing Z' Models
• Flavor changing single top quark production channels at e^+e^- colliders in the effective Lagrangian description
• Probing the Anomalous FCNC Interactions in Top-Higgs Final State and Charge Ratio Approach
• Testing flavor-changing neutral currents in the rare decays t->cViVj
• Single top quark production as a probe of anomalous $tq\gamma$ and $tqZ$ couplings at the FCC-ee
• Testing Lepton Flavor Universality with Pion, Kaon, Tau, and Beta Decays
• Constraining four-fermion operators using rare top decays
• Four-Fermi Effective Operators in Top-Quark Production and Decay
• R-parity violating effects in top quark FCNC productions at LHC
• Lepton Flavour Violating top decays at the LHC
• Search for supersymmetry in final states with missing transverse momentum and three or more $b$-jets in 139 fb${}^{-1}$ of proton$-$proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• FCNC-induced heavy-quark events at the LHC from Supersymmetry
• New flavor physics in di- and tri-lepton events from single-top at the LHC and beyond
• Probing flavor constrained SMEFT operators through $tc$ production at the Muon collider
• Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at $\sqrt{s}=13$ TeV
• UV physics from IR features: new prospects from top flavor violation
• Constraining rare B decays by ${\mu }^{+}{\mu }^{-}\to tc$ at future lepton colliders
• Probing anomalous $tq\gamma$ and $tqg$ couplings via single top production in association with photon at FCC-hh
• Search for single top quark production via contact interactions at LEP2
• Top FCNC interactions through dimension six four-fermion operators at the electron proton collider
• Probing four-fermion operators in the triple top production at future hadron colliders
• Probing the anomalous $tq\gamma$ couplings through single top production at the future lepton-hadron colliders
• Same-sign top pair plus $W$ production in flavor changing vector and scalar models
• Search for pair-produced higgsinos decaying via Higgs or $Z$ bosons to final states containing a pair of photons and a pair of $b$-jets with the ATLAS detector
• 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
• 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

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