Vector-like Singlet Quarks: a Roadmap

Abstract

We review the theory and phenomenology of isosinglet vector-like quarks (VLQs). In recent years, interest in VLQs has been increasing, due to their contributions to new physics effects that can be tested in experiments at LHC and High-Luminosity LHC. The similarities of models with isosinglet VLQs and the seesaw framework in the leptonic sector are pointed out. The existence of VLQs leads to flavour-changing neutral currents at tree level and deviations from unitarity of the CKM matrix, introducing rich phenomenological implications. These new effects are naturally suppressed by the masses of the new quarks, that are constrained to be above the electroweak scale. In addition, striking new effects can be achieved with the inclusion of an extra complex scalar singlet. Such a minimal extension of the SM can give rise to new sources of CP violation with profound theoretical implications, allowing for a solution to the strong CP problem and a possible explanation for the baryon asymmetry of the Universe. We list and explain strong motivations to consider this class of models. We also briefly review how models with VLQs can be matched to the SM effective field theory (SMEFT). A detailed analysis of flavour observables that can be affected by the presence of VLQs is presented. Current bounds from collider searches of VLQs are summarized. We point out that the discovery of VLQs can be within the reach of present or future colliders being planned.

arXiv comment121 pages, 7 figures, 7 tables. Work intended as a review. Comments and references added; typos corrected. New appendix on UV completions; section 2.3 expanded. Matches version published in Physics Reports

References in corpus (207)

• A Large Mass Hierarchy from a Small Extra Dimension
• Weak Decays Beyond Leading Logarithms
• Dimension-Six Terms in the Standard Model Lagrangian
• An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
• Precision Electroweak Measurements on the Z Resonance
• Electric dipole moments as probes of new physics
• Renormalization Group Evolution of the Standard Model Dimension Six Operators III: Gauge Coupling Dependence and Phenomenology
• CP violating decays in leptogenesis scenarios
• Renormalization Group Evolution of the Standard Model Dimension Six Operators II: Yukawa Dependence
• Measurement of the permanent electric dipole moment of the neutron
• Baryogenesis from a Lepton Asymmetric Universe
• A Revised Experimental Upper Limit on the Electric Dipole Moment of the Neutron
• Update of the global electroweak fit and constraints on two-Higgs-doublet models
• A handbook of vector-like quarks: mixing and single production
• Reduced Limit on the Permanent Electric Dipole Moment of ${}^{199}$Hg
• The Rare Decays $K\to \pi \nu \bar{\nu }$, $B\to X\nu \bar{\nu }$ and $B\to l^{+}{l}^{-}$ -- An Update
• Quarks and Leptons Beyond the Third Generation
• CP Asymmetry in Majorana Neutrino Decays
• Effective description of general extensions of the Standard Model: the complete tree-level dictionary
• Effects of new leptons in Electroweak Precision Data
• Patterns of Deviation from the Standard Model
• Identifying top partners at LHC
• Reduced hadronic uncertainty in the determination of $V_{ud}$
• Light Top Partners for a Light Composite Higgs
• Beyond S, T and U
• Model Independent Framework for Searches of Top Partners
• CP-violation from non-unitary leptonic mixing
• New physics explanations of $a_{\mu }$ in light of the FNAL muon $g-2$ measurement
• Radiative Corrections to Neutron and Nuclear Beta Decays Revisited
• Observable contributions of new exotic quarks to quark mixing
• Correlations among new CP violating effects in Delta F = 2 observables
• On the Standard Model prediction for BR(B{s,d} to mu+ mu-)
• Search for $K_L\to {\pi }^0\nu \overline{\nu }$ and $K_L\to {\pi }^0{X}^0$ Decays at the J-PARC KOTO Experiment
• Dispersive Evaluation of the Inner Radiative Correction in Neutron and Nuclear $\beta$-decay
• Effects of mixing with quark singlets
• Dirac, Majorana and Weyl fermions
• Precision Measurements and CKM Unitarity
• Impact of a Higgs boson at a mass of 126 GeV on the standard model with three and four fermion generations
• Combination of the searches for pair-produced vector-like partners of the third-generation quarks at $\sqrt{s}=$ 13 TeV with the ATLAS detector
• On the short-distance constraints from K_{L,S} -> mu^+ mu^-
• Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Rare $B$ Decays as Tests of the Standard Model
• Automorphisms in Gauge Theories and the Definition of CP and P
• The CKM unitarity problem: A trace of new physics at the TeV scale?
• Effective description of quark mixing
• Sealing the fate of a fourth generation of fermions
• Joint lattice QCD - dispersion theory analysis confirms the quark-mixing top-row unitarity deficit
• Patterns of Flavour Violation in Models with Vector-Like Quarks
• Quark Singlets: Implications and Constraints
• Relating the scalar flavour-changing neutral couplings to the CKM matrix
• epsilon'/epsilon and Rare K and B Decays in the MSSM
• Model-Independent Searches for New Quarks at the LHC
• A Proof of Concept for Matchete: An Automated Tool for Matching Effective Theories
• The seesaw mechanism at arbitrary order: disentangling the small scale from the large scale
• Electroweak Corrections to $B_{s,d}\to {\ell }^{+}{\ell }^{-}$
• New Vector-Like Fermions and Flavor Physics
• Determining the Quark Mixing Matrix From CP-Violating Asymmetries
• Search for pair and single production of new heavy quarks that decay to a $Z$ boson and a third-generation quark in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Leptonic CP Asymmetries in Flavor-changing H0 Decays
• New Physics in B-Bbar mixing in the light of recent LHCb data
• Three-loop QCD corrections to B_s -> mu^+ mu^-
• Rare top decays t -> c gamma, t -> c g and CKM unitarity
• Standard Model $\mathcal{O}(\alpha )$ renormalization of $g_A$ and its impact on new physics searches
• Flavour physics of the RS model with KK masses reachable at LHC
• Theory and Phenomenology of Exotic Isosinglet Quarks and Squarks
• Global Electroweak Fit and Vector-Like Leptons in Light of the Cabibbo Angle Anomaly
• Search for a heavy top-quark partner in final states with two leptons with the ATLAS detector at the LHC
• Waiting for Precise Measurements of K^+->pi^+ nu nu and K_L->pi^0 nu nu
• Heavy Quarks Above the Top at the Tevatron
• Loop effects of heavy new scalars and fermions in $b\to s{\mu }^{+}{\mu }^{-}$
• Bounds and Decays of New Heavy Vector-like Top Partners
• Search for Fermion-Pair Decays $Q\Qbar \to (\t\Wmp)(\tbar\Wpm)$ in Same-Charge Dilepton Events
• Search for pair production of up-type vector-like quarks and for four-top-quark events in final states with multiple $b$-jets with the ATLAS detector
• Electroweak axial structure functions and improved extraction of the $V_{ud}$ CKM matrix element
• Collider Phenomenology of Gauge-Higgs Unification Scenarios in Warped Extra Dimensions
• Search for pair production of heavy vector-like quarks decaying to high-$p_{\text{T}}$ $W$ bosons and $b$ quarks in the lepton-plus-jets final state in $pp$ collisions at $\sqrt{s}$=13 TeV with the ATLAS detector
• Phenomenological Consequences of sub-leading Terms in See-Saw Formulas
• Scrutinizing CKM unitarity with a new measurement of the $K_{\mu 3}/K_{\mu 2}$ branching fraction
• Search for pair production of vector-like quarks in the fully hadronic final state
• Search for pair production of vector-like top quarks in events with one lepton, jets, and missing transverse momentum in $\sqrt{s}=13$ TeV pp collisions with the ATLAS detector
• Standard-model prediction of ${\epsilon }_K$ with manifest CKM unitarity
• Effects of theta on the deuteron binding energy and the triple-alpha process
• Quasi-Dirac neutrinos at the LHC
• Search for a Vector-like Quark with Charge 2/3 in t + Z Events from pp Collisions at sqrt(s) = 7 TeV
• Analysis of events with $b$-jets and a pair of leptons of the same charge in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Solving the strong CP problem with supersymmetry
• Search for heavy, top-like quark pair production in the dilepton final state in pp collisions at sqrt(s) = 7 TeV
• The CKM parameters in the SMEFT
• R_b and New Physics: A Comprehensive Analysis
• Novel signatures for vector-like quarks
• LHC Signatures of Two-Higgs-Doublets with Fourth Family
• On the Statistical Treatment of the Cabibbo Angle Anomaly
• Search for heavy bottom-like quarks decaying to an electron or muon and jets in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
• New Physics and Evidence for a Complex CKM
• LHC Signatures of Warped-space Vectorlike Quarks
• Direct Bounds on Heavy Top-Like Quarks With Standard and Exotic Decays
• First-Generation New Physics in Simplified Models: From Low-Energy Parity Violation to the LHC
• A CP-conserving multi-Higgs model without real basis
• Search for down-type fourth generation quarks with the ATLAS detector in events with one lepton and hadronically decaying W bosons
• Single Vectorlike Quark Production at the LHC
• Study of the $K_L\to {\pi }^0\nu \overline{\nu }$ Decay at the J-PARC KOTO Experiment
• Search for pair produced fourth-generation up-type quarks in pp collisions at sqrt(s) = 7 TeV with a lepton in the final state
• Search for pair production of heavy top-like quarks decaying to a high-pT W boson and a b quark in the lepton plus jets final state at sqrt(s)=7 TeV with the ATLAS detector
• Universality limits on bulk fermions
• Search for vector-like quarks in events with two oppositely charged leptons and jets in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons
• Search for single production of vector-like quarks decaying to a top quark and a W boson in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Implications of Higgs Searches on the Four Generation Standard Model
• Search for vector-like T quarks decaying to top quarks and Higgs bosons in the all-hadronic channel using jet substructure
• Search for single production of vector-like quarks decaying into $Wb$ in $pp$ collisions at $\sqrt{s}=$ 8 TeV with the ATLAS detector
• Single production of vector-like quarks with large width at the Large Hadron Collider
• Production of extra quarks at the Large Hadron Collider beyond the Narrow Width Approximation
• Aligned and Spontaneous Flavor Violation
• Majorana vs Pseudo-Dirac Neutrinos at the ILC
• Searching for Dark Photons with Maverick Top Partners
• Interpreting the $W$-mass anomaly in the vectorlike quark models
• Framework for Model Independent Analyses of Multiple Extra Quark Scenarios
• Large $t\to cZ$ as a Sign of Vector-Like Quarks in Light of the $W$ Mass
• The Hunt for New Physics in the Flavour Sector with up vector-like quarks
• LHC Signatures of a Vector-like b'
• Search for single production of vector-like quarks decaying to a b quark and a Higgs boson
• Global Fit of Modified Quark Couplings to EW Gauge Bosons and Vector-Like Quarks in Light of the Cabibbo Angle Anomaly
• Search for heavy vector-like quarks coupling to light quarks in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Search for pair-produced heavy quarks decaying to Wq in the two-lepton channel at sqrt(s) = 7 TeV with the ATLAS detector
• Search for pair production of a heavy up-type quark decaying to a W boson and a b quark in the lepton+jets channel with the ATLAS detector
• Masses, Mixings, Yukawa Couplings and their Symmetries
• Search for a Heavy Top-Like Quark in p\bar{p} Collisions at {\surd}s = 1.96 TeV
• Search for New Particles Leading to Z+jets Final States in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV
• Search for electroweak production of a vector-like T quark using fully hadronic final states
• Search for pair production of a new quark that decays to a Z boson and a bottom quark with the ATLAS detector
• A search for bottom-type, vector-like quark pair production in a fully hadronic final state in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• The CKM Phase and $\bar{\theta }$ in Nelson-Barr Models
• Loop Induced Single Top Partner Production and Decay at the LHC
• Novel Interpretation Strategy for Searches of Singly Produced Vector-like Quarks at the LHC
• CP violation from new quarks in the chiral limit
• Vector-like Quark Interpretation for the CKM Unitarity Violation, Excess in Higgs Signal Strength, and Bottom Quark Forward-Backward Asymmetry
• Search for pair-production of vector-like quarks in $pp$ collision events at $\sqrt{s}=13$ TeV with at least one leptonically decaying $Z$ boson and a third-generation quark with the ATLAS detector
• Phenomenology of 2HDM with VLQs
• Search for Production of Heavy Particles Decaying to Top Quarks and Invisible Particles in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
• Search for electroweak production of a vector-like quark decaying to a top quark and a Higgs boson using boosted topologies in fully hadronic final states
• Search for a fourth generation t' quark in ppbar collisions at sqrt{s}=1.96 TeV
• New Fermions at the LHC and Mass of the Higgs Boson
• Modelling vector-like quarks in partial compositeness framework
• Sequestering CP Violation and GIM-Violation with Warped Extra Dimensions
• Flavour Dynamics: CP Violation and Rare Decays
• Unificaxion
• $D^0-{\bar{D}}^0$ Mixing in the Presence of Isosinglet Quarks
• Higgs Vacuum Stability with Vector-like Fermions
• Search for pair-produced vector-like top and bottom partners in events with large missing transverse momentum in pp collisions with the ATLAS detector
• Dirac vs. Majorana HNLs (and their oscillations) at SHiP
• Search for New $T^{\prime }$ Particles in Final States with Large Jet Multiplicities and Missing Transverse Energy in ppbar Collisions at sqrt(s) = 1.96 TeV
• ${\epsilon }^{\prime }/\epsilon$ in the Standard Model at the Dawn of the 2020s
• Search for single production of a heavy vector-like T quark decaying to a Higgs boson and a top quark with a lepton and jets in the final state
• Roadmap to explore vectorlike quarks decaying to a new scalar or pseudoscalar
• Portals into Higgs vacuum stability
• Shedding Light on Top Partner at the LHC
• Ruling Out the Massless Up-Quark Solution to the Strong CP Problem by Computing the Topological Mass Contribution with Lattice QCD
• Hunting for top partner with a new signature at the LHC
• Supersymmetric Solutions to the Strong CP Problem
• Search for single production of the heavy vectorlike $T$ quark with $T\to th$ and $h\to \gamma \gamma$ at the high-luminosity LHC
• Prospects for New Physics from gauge Left-Right-Colour-Family Grand Unification hypothesis
• Super-Soft CP Violation
• Discovery prospects of a vectorlike top partner decaying to a singlet boson
• The size of chi = arg (-Vts Vtb* Vcs* Vcb) and physics beyond the Standard Model
• Yet Another Extension of the Standard Model: Oases in the Desert?
• Search for single vector-like quarks in ppbar collisions at sqrt(s) = 1.96 TeV
• Asymmetry in flavour changing electromagnetic transitions of vector-like quarks
• Triangulating an exotic T quark
• Search for vector-like light-flavor quark partners in proton-proton collisions at $\sqrt{s}=$8 TeV
• Unitarity Triangles and the Search for New Physics
• Machine learning-enhanced search for a vectorlike singlet $B$ quark decaying to a singlet scalar or pseudoscalar
• Exploring maverick top partner decays at the LHC
• Some Remarks on Anthropic Approaches to the Strong CP Problem
• Type-I Seesaw with eV-Scale Neutrinos
• Vacuum Induced CP Violation Generating a Complex CKM Matrix with Controlled Scalar FCNC
• A Natural Model of Spontaneous CP Violation
• A Complete Solution to the Strong CP Problem: a SUSY Extension of the Nelson-Barr Model
• Nondecoupling of a terascale isosinglet quark and rare K and B decays
• Vector-Like Quarks and Leptons, SU(5) $\otimes$ SU(5) Grand Unification, and Proton Decay
• Consequences of vector-like quarks of Nelson-Barr type
• Solving the strong CP problem with non-conventional CP
• A Grand-Unified Nelson-Barr Model
• High quality Nelson-Barr solution to the strong CP problem with $\theta =\pi$
• A Grand Unified Parity Solution to Strong CP Problem
• The E6 inspired isosinglet quark and the Higgs boson
• Vector-like quarks with non-renormalizable interactions
• Constraints on the quark mixing matrix with vector-like quarks
• Top-Charm flavor changing contributions to the effective $bsZ$ vertex
• Search for pair production of the heavy vectorlike top partner in same-sign dilepton signature at the HL-LHC
• New (virtual) Physics in the Era of the LHC
• Baryon Asymmetric Universe from Spontaneous CP Violation
• An SU(6) GUT Origin of the TeV-Scale Vector-like Particles Associated with the 750 GeV Diphoton Resonance
• Effective field theory for vector-like leptons and its collider signals
• Solving the strong CP problem with horizontal gauge symmetry
• Decays of the Heavy Top and New Insights on ${\epsilon }_K$ in a one-VLQ Minimal Solution to the CKM Unitarity Problem
• Leptonic CP violation from a vector-like lepton
• Parameter counting in models with global symmetries
• Manifestation of a singlet heavy up-type quark in the branching ratios of rare decays K to πν\barν, B to πν\barν and B to K ν\barν
• Explicit parametrization of more than one vector-like quark of Nelson-Barr type
• Effective theory analysis for vector-like quark model
• CP-odd and CP-even Weak-Basis Invariants in the Presence of Vector-Like Quarks
• Down type iso-singlet quarks at the HL-LHC and FCC-hh
• Alternative Renormalizable Minimal SO(10) GUTs and Data Fitting
• Variant Nelson-Barr Mechanism with Minimal Flavor Violation
• Dark-sector seeded solution to the strong CP problem
• New Physics and CP Angles Measurement at B Factory
• Phenomenological aspects of composite Higgs scenarios: exotic scalars and vector-like quarks

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