Precision Constraints on Extra Fermion Generations

Abstract

There has been renewed interest in the possibility of additional fermion generations. At the same time there have been significant changes in the relevant electroweak precision constraints, in particular, in the interpretation of several of the low energy experiments. We summarize the various motivations for extra families and analyze them in view of the latest electroweak precision data.

5 pages, 2 figures, minor changes

References in corpus (36)

• A Large Mass Hierarchy from a Small Extra Dimension
• Precision Electroweak Measurements on the Z Resonance
• HiggsBounds: Confronting Arbitrary Higgs Sectors with Exclusion Bounds from LEP and the Tevatron
• A Precise Determination of Electroweak Parameters in Neutrino-Nucleon Scattering
• Violations of fundamental symmetries in atoms and tests of unification theories of elementary particles
• Parton distributions incorporating QED contributions
• Four Generations and Higgs Physics
• Quarks and Leptons Beyond the Third Generation
• Extra Families, Higgs Spectrum and Oblique Corrections
• Precision Measurement of the Weak Mixing Angle in Moller Scattering
• Precision determination of electroweak coupling from atomic parity violation and implications for particle physics
• Extra vector-like matter and the lightest Higgs scalar boson mass in low-energy supersymmetry
• Four Statements about the Fourth Generation
• Search for Heavy Neutral and Charged Leptons in e+ e- Annihilation at LEP
• The Discrepancy Between tau and e+e- Spectral Functions Revisited and the Consequences for the Muon Magnetic Anomaly
• Electroweak Baryogenesis and New TeV Fermions
• String Consistency for Unified Model Building
• How much space is left for a new family?
• A Global Fit to Extended Oblique Parameters
• Extra quark-lepton generations and precision measurements
• Testing the Standard Model by precision measurement of the weak charges of quarks
• Isovector EMC effect explains the NuTeV anomaly
• Difference in B^+ and B^0 Direct CP Asymmetry as Effect of a Fourth Generation
• Large Time-dependent CP Violation in B_s^0 System and Finite D^0-D^0bar Mass Difference in Four Generation Standard Mode
• Search for Fermion-Pair Decays $Q\Qbar \to (\t\Wmp)(\tbar\Wpm)$ in Same-Charge Dilepton Events
• Experimental constraints on fourth generation quark masses
• Constraints on Mass Spectrum of Fourth Generation Fermions and Higgs Bosons
• Electroweak Symmetry Breaking from a Holographic Fourth Generation
• Asymmetric Orbifolds and Higher Level Models
• Radiatively Generated Isospin Violations in the Nucleon and the NuTeV Anomaly
• Minimal SU(5) Resuscitated by Long-Lived Quarks and Leptons
• Negative T from a dynamical left-handed neutrino mass
• Search for New Particles Leading to Z+jets Final States in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV
• The strongly coupled fourth family and a first-order electroweak phase transition (I) quark sector
• Natural fourth generation of leptons
• Collider signals of a composite Higgs in the Standard Model with four generations

Cited by in corpus (90)

• Simplified Models for LHC New Physics Searches
• Updated Status of the Global Electroweak Fit and Constraints on New Physics
• Impact of a Higgs boson at a mass of 126 GeV on the standard model with three and four fermion generations
• Sealing the fate of a fourth generation of fermions
• Less space for a new family of fermions
• Model-Independent Searches for New Quarks at the LHC
• Breaking Local Baryon and Lepton Number at the TeV Scale
• Unravelling an extended quark sector through multiple Higgs production?
• Search for heavy bottom-like quarks in 4.9 inverse femtobarns of pp collisions at sqrt(s) = 7 TeV
• Higgs boson pair production in new physics models at hadron, lepton, and photon colliders
• Minimal Conformal Technicolor and Precision Electroweak Tests
• Lepton Flavour Violation in the Presence of a Fourth Generation of Quarks and Leptons
• Electroweak Precision Tests of the Standard Model after the Discovery of the Higgs Boson
• Source of CP Violation for the Baryon Asymmetry of the Universe
• Co-genesis of Matter and Dark Matter with Vector-like Fourth Generation Leptons
• Flavor and CP Violation with Fourth Generations Revisited
• Higgs production and decay with a fourth Standard-Model-like fermion generation
• Constraints on the Four-Generation Quark Mixing Matrix from a Fit to Flavor-Physics Data
• Joint analysis of Higgs decays and electroweak precision observables in the Standard Model with a sequential fourth generation
• Minimal Vector-like leptonic Dark Matter and Signatures at the LHC
• Implications of String Constraints for Exotic Matter and Z' s Beyond the Standard Model
• Two Higgs doublets with 4th generation fermions - models for TeV-scale compositeness
• Dynamical Electroweak Symmetry Breaking with a Heavy Fourth Generation
• Search for a Heavy Bottom-like Quark in pp Collisions at sqrt(s) = 7 TeV
• Hiding a Heavy Higgs Boson at the 7 TeV LHC
• Direct Mass Limits for Chiral Fourth-Generation Quarks in All Mixing Scenarios
• Scalar Dark Matter and Standard Model with Four Generations
• Towards the fate of natural composite Higgs model through single $t^{\prime }$ search at the 8 TeV LHC
• Constraining the mixing matrix for Standard Model with four generations: time dependent and semi-leptonic CP asymmetries in $B_d^0$, $B_s$ and $D^0$
• BSM Higgs Physics in the Exclusive Forward Proton Mode at the LHC
• Higgs data confronts Sequential Fourth Generation Fermions in the Higgs Triplet Model
• Relating B_s Mixing and B_s -> mu+mu- with New Physics
• Closing in on a perturbative fourth generation
• A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC
• Searches for Higgs bosons in pp collisions at sqrt(s) = 7 and 8 TeV in the context of four-generation and fermiophobic models
• Quark masses and mixings in the RS1 model with a condensing 4th generation
• Four Generations, Higgs Physics, and the MSSM
• Fourth Generation Bound States
• Masses of a Fourth Generation with Two Higgs Doublets
• Higgs Boson Production via Gluon Fusion in the Standard Model with four Generations
• Flavoured gauge extension of singlet-doublet fermionic dark matter: neutrino mass, high scale validity and collider signatures
• Proton stability from a fourth family
• Enhanced spin-dependent parity non-conservation effect in the $7s{}^2{S}_{1/2}\to 6d{}^2{D}_{5/2}$ transition in Fr: A possibility for unambiguous detection of nuclear anapole moment
• Saving fourth generation and baryon number by living long
• An A_5 Model of Four Lepton Generations
• Neutrino dark matter candidate in fourth generation scenarios
• Large mass splittings for fourth generation fermions allowed by LHC Higgs exclusion
• SuperTopcolor
• Sub-TeV Singlet Scalar Dark Matter and Electroweak Vacuum Stability with Vector Like Fermions
• A Search for the Fourth SM Family: Tevatron still has a Chance
• $CP$ asymmetries in the rare top decays $t\to c\gamma$ and $t\to cg$
• Revisiting Constraints on Fourth Generation Neutrino Masses
• OPUCEM: A Library with Error Checking Mechanism for Computing Oblique Parameters
• A hybrid 4${}^{\text{th}}$ generation: Technicolor with top-seesaw
• Probing the fourth generation Majorana neutrino dark matter
• Relativistic coupled-cluster analysis of parity nonconserving amplitudes and related properties of the $6s{}^2{S}_{1/2}-5d{}^2{D}_{3/2;5/2}$ transitions in ${}^{133}$Cs
• Ultraviolet Completions of Axigluon Models and Their Phenomenological Consequences
• Three Extra Mirror or Sequential Families: a Case for Heavy Higgs and Inert Doublet
• Fourth Generation Majorana Neutrinos
• Electroweak Precision Observables within a Fourth Generation Model with General Flavour Structure
• Non-Linear Single Higgs MSSM
• Neutrino Masses and a Fourth Generation of Fermions
• Fourth generation quark mass limits in CKM-element space
• LHC Implications of the WIMP Miracle and Grand Unification
• Neutrino masses from new generations
• Minimal gauge origin of baryon triality and flavorful signatures at the LHC
• Fourth generation Majorana neutrino, dark matter and Higgs physics
• A Search for leptophilic Z_(l) boson at future linear colliders
• A Search for the Fourth SM Family Quarks through Anomalous Decays
• Phenomenology of Strongly Coupled Chiral Gauge Theories
• Measuring the Magnitude of the Fourth-Generation CKM4 Matrix Element V_{t'b'}
• An optical lattice based method for precise measurements of atomic parity violation
• Coherent mixing in three and four quark generations
• Chiral heavy fermions in a two Higgs doublet model: 750 GeV resonance or not
• Vector like leptons with extended Higgs sector
• Scalar Decay Constant and Yukawa Coupling in Walking Gauge Theories
• A note on the coupling of the techni-dilaton to the weak bosons
• Bounds on fourth generation induced Lepton Flavour Violating double insertions in Supersymmetry
• A variant two-Higgs doublet model with a new Abelian gauge symmetry
• Gauged $L_e-L_{\mu }-L_{\tau }$ symmetry, fourth generation, neutrino mass and dark matter
• Electroweak Dark Matter
• Anomalous single production of fourth family up type quark associated with neutral gauge bosons at the LHC
• Pair Production of Fourth Family Charged Sleptons at $e^{+}{e}^{-}$ Colliders
• Semileptonic B to Scalar meson Decays in the Standard Model with Fourth Generation
• Z'-> ggg decay in left-right symmetric models with three and four fermion families
• A Model with Chiral Quarks of Electric Charges -4/3 and 5/3
• Flavour physics with a 4th generation
• Highlights of Flavour Violation in the Presence of a 4th Generation
• Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing
• Relating B_s Mixing and B_s->mu+mu- with New Physics - An Update