Studying flavor-changing neutral tqZ couplings: Current constraints and future prospects

Abstract

Possible non-standard tuZ and tcZ interactions, which induce flavor-changing neutral-current decays of the top quark, are studied in the effective-Lagrangian framework. The corresponding Lagrangian consists of four kinds of non-standard couplings coming from SU(3)xSU(2)xU(1) invariant dimension-6 effective operators. The four coupling constants in each interaction are treated as complex numbers independent of each other, and constraints on them are derived by using the present experimental limits of the branching fractions for t -> u Z and t -> c Z processes. Future improvements of those constraints are also discussed as well as possibilities of measurements of these couplings at the High-Luminosity Large Hadron Collider.

arXiv commentMain text divided into several sections and some comments plus related references added (No change in results). Final version accepted for Mod.Phys.Lett.A

References in corpus (23)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• Dimension-Six Terms in the Standard Model Lagrangian
• A minimal set of top anomalous couplings
• Patterns of Deviation from the Standard Model
• Top-Quark Decay at Next-to-Next-to-Leading Order in QCD
• A global approach to top-quark flavor-changing interactions
• Top-Quark Decay Via Flavor-Changing Neutral Currents at Hadron Colliders
• Top-Charm Associated Production in High Energy $e^{+}{e}^{-}$ Collisions
• New Physics effects in the flavor-changing neutral couplings of the Top quark
• Multilepton production via top flavour-changing neutral couplings at the CERN LHC
• Zt and γt production via top flavour-changing neutral couplings at the Fermilab Tevatron
• Constraints on top quark FCNC from electroweak precision measurements
• Single top quark production as a probe of anomalous $tq\gamma$ and $tqZ$ couplings at the FCC-ee
• Dimension six FCNC operators and top production at the LHC
• Direct top-quark decay width measurement in the $t\bar{t}$ lepton+jets channel at $\sqrt{s}$=8 TeV with the ATLAS experiment
• Signatures of NP models in top FCNC decay t --> c(u) l+ l-
• Searches for anomalous $tqZ$ couplings from the trilepton signal of $tZ$ associated production at the 14 TeV LHC
• Search for top quark flavour changing neutral currents in same-sign top quark production
• Ultraboosted $Zt$ and $\gamma t$ production at the HL-LHC and FCC-hh
• Model Independent Predictions for Rare Top Decays with Weak Coupling
• Impact of FCNC top quark interactions on BR(t -> b W)
• Top quark physics in the Large Hadron Collider era

Cited by in corpus (2)

• Correlations in flavor-changing tqZ couplings constrained via experimental data
• Effective Lagrangian Approach to Top Decay via Flavor Changing Neutral Current