Dynamical origin of flavor hierarchies in a warped extra dimension

Abstract

Extensions of the Standard Model featuring a warped extra dimension compactified on an $S^1/{\mathbb{Z}}_2$ orbifold, in which the fermions and gauge bosons live in the bulk of the fifth dimension, offer one of the most compelling mechanisms for addressing both the hierarchy problem and the flavor puzzle of the Standard Model. However, the five-dimensional mass terms of bulk fermions must be odd functions on the orbifold, and as such they should be described by a field depending on the coordinate of the extra dimension. We demonstrate the feasibility of dynamically generating these fermion bulk masses with a bulk scalar field in warped extra dimensions. The bulk scalar acquires a vacuum expectation value, which is odd under the orbifold symmetry and gives rise to the fermion bulk masses through non-universal Yukawa-like interactions. Like in the conventional Randall-Sundrum setup, the localization of the different fermion zero modes along the extra dimension naturally explains the observed flavor structure and four-dimensional mass hierarchy of the SM fermions. We study the phenomenological implications of the backreaction on the metric and the modified fermion profiles due to the bulk scalar field on electroweak precision and flavor observables. Using up-to-date data, we show that the contributions to the $S$, $T$, and ${\epsilon }_K$ parameters require the mass of the first Kaluza-Klein gluon resonance to be of order 14 and 10 TeV in the minimal and the custodial model, respectively, regardless of the effect of the backreaction. Furthermore, effective flavor-changing interactions among the SM fermions induced by the bulk scalar are discussed. We also comment on the potential impact of the Higgs portal interaction of the bulk scalar on the couplings of the Higgs boson.

arXiv comment38 pages, 13 figures; v2: corrected calculation of the oblique parameters, figure 7 and table 1 changed, matches version accepted for publication in JHEP

References in corpus (58)

• Gauge Theory Correlators from Non-Critical String Theory
• A Large Mass Hierarchy from a Small Extra Dimension
• The Large N Limit of Superconformal Field Theories and Supergravity
• Modulus Stabilization with Bulk Fields
• AdS/CFT Correspondence and Symmetry Breaking
• Bulk Fields and Supersymmetry in a Slice of AdS
• Neutrino masses and mixings in non-factorizable geometry
• A custodial symmetry for Zbb
• Electroweak symmetry breaking after LEP1 and LEP2
• Holography and Phenomenology
• Comments on the Holographic Picture of the Randall-Sundrum Model
• Bulk Gauge Fields in the Randall-Sundrum Model
• Radion Dynamics and Electroweak Physics
• Flavor Structure of Warped Extra Dimension Models
• Fermion Masses, Mixings and Proton Decay in a Randall-Sundrum Model
• Delta M_K and epsilon_K in SUSY at the Next-to-Leading order
• Update of the global electroweak fit and constraints on two-Higgs-doublet models
• Higgs Boson Studies at Future Particle Colliders
• The Flavor of the Composite Pseudo-Goldstone Higgs
• Conformality Lost
• Flavor Physics in the Randall-Sundrum Model: I. Theoretical Setup and Electroweak Precision Tests
• Light Kaluza-Klein States in Randall-Sundrum Models with Custodial SU(2)
• Delta F=2 Observables and Fine-Tuning in a Warped Extra Dimension with Custodial Protection
• Next-to-Next-to-Leading-Order Charm-Quark Contribution to the CP Violation Parameter epsilon_K and Delta M_K
• Electroweak constraints on warped models with custodial symmetry
• B-factory Signals for a Warped Extra Dimension
• Holography for fermions
• Randall-Sundrum models and the regularized AdS/CFT correspondence
• Rare K and B Decays in a Warped Extra Dimension with Custodial Protection
• The Effective Lagrangian in the Randall-Sundrum Model and Electroweak Physics
• Higgs Mediated FCNC's in Warped Extra Dimensions
• Flavor Physics in the Randall-Sundrum Model: II. Tree-Level Weak-Interaction Processes
• Precision Electroweak Data and Unification of Couplings in Warped Extra Dimensions
• Chiral fermions, orbifolds, scalars and fat branes
• Warped 5-Dimensional Models: Phenomenological Status and Experimental Prospects
• The Custodial Randall-Sundrum Model: From Precision Tests to Higgs Physics
• Large N Field Theory and AdS Tachyons
• The Gaugephobic Higgs
• Warped Fermions and Precision Tests
• Suppressing Electroweak Precision Observables in 5D Warped Models
• TASI Lectures on a Holographic View of Beyond the Standard Model Physics
• flavio: a Python package for flavour and precision phenomenology in the Standard Model and beyond
• Next to Minimal Flavor Violation
• Goldberger-Wise variations: stabilizing brane models with a bulk scalar
• Off-the-Wall Higgs in the Universal Randall-Sundrum Model
• Higgs Production in a Warped Extra Dimension
• 5D Perspective on Higgs Production at the Boundary of a Warped Extra Dimension
• The Fermion Mass Hierarchy in Models with Warped Extra Dimensions and a Bulk Higgs
• Bounds on Warped Extra Dimensions from a Standard Model-like Higgs Boson
• A Solution to the Flavor Problem of Warped Extra-Dimension Models
• Little Randall-Sundrum models: epsilon_K strikes again
• Diphoton Resonance from a Warped Extra Dimension
• Higgs Production and Decay in Models of a Warped Extra Dimension with a Bulk Higgs
• A Natural Hierarchy and a low New Physics scale from a Bulk Higgs
• Low-energy effective theory from a non-trivial scalar background in extra dimensions
• Metastable Kinks in the Orbifold
• Higgs Decay into Two Photons at the Boundary of a Warped Extra Dimension
• Scalar Kinks in Warped Extra Dimensions

Cited by in corpus (14)

• Flavor Non-universal Pati-Salam Unification and Neutrino Masses
• Minimal Froggatt-Nielsen Textures
• A light dilaton at the LHC
• Holographic models of composite Higgs in the Veneziano limit. Part II. Fermionic sector
• A warped scalar portal to fermionic dark matter
• Kinetic Mixing from Kaluza-Klein Modes: A Simple Construction for Portal Matter
• Probing the electron-to-proton mass ratio gradient in the Milky Way with class I methanol masers
• Dilaton portal in strongly interacting twin Higgs models
• Dynamical generation of quark/lepton mass hierarchy in an extra dimension
• Towards a Model of Quarks and Leptons
• Freeze-in self-interacting dark matter in warped extra dimension
• Local $SU(2)\times U(1)$ Quark Flavor Symmetry in the RS Bulk
• Moduli Dynamics in Effective Nested Warped Geometry in Four Dimensions and Some Cosmological Implications
• Taming the ${\epsilon }_K$ in Little Randall Sundrum Models