Large Leptonic Dirac CP Phase from Broken Democracy with Random Perturbations

Abstract

A large value of the leptonic Dirac CP phase can arise from broken democracy, where the mass matrices are democratic up to small random perturbations. Such perturbations are a natural consequence of broken residual ${\mathbb{S}}_3$ symmetries that dictate the democratic mass matrices at leading order. With random perturbations, the leptonic Dirac CP phase has a higher probability to attain a value around $\pm \pi /2$. Comparing with the anarchy model, broken democracy can benefit from residual ${\mathbb{S}}_3$ symmetries, and it can produce much better, realistic predictions for the mass hierarchy, mixing angles, and Dirac CP phase in both quark and lepton sectors. Our approach provides a general framework for a class of models in which a residual symmetry determines the general features at leading order, and where, in the absence of other fundamental principles, the symmetry breaking appears in the form of random perturbations.

arXiv comment14 pages, 5 figures; references added; match the PLB version

References in corpus (41)

• Status of neutrino oscillations 2018: first hint for normal mass ordering and improved CP sensitivity
• Mass and Flavor Mixing Schemes of Quarks and Leptons
• Neutrino Mass Anarchy
• Lepton mixing and discrete symmetries
• Lepton Mass Hierarchy and Neutrino Oscillations
• The Unique Horizontal Symmetry of Leptons
• Large Leptonic Flavor Mixing and the Mass Spectrum of Leptons
• The Horizontal Symmetry for Neutrino Mixing
• Anarchy and Hierarchy
• Atmospheric Neutrino Oscillation and a Phenomenological Lepton Mass Matrix
• Residual Symmetries for Neutrino Mixing with a Large theta_13 and Nearly Maximal delta_D
• Z_2 Symmetry Prediction for the Leptonic Dirac CP Phase
• Leptogenesis with Almost Degenerate Majorana Neutrinos
• Discrete symmetries and model-independent patterns of lepton mixing
• Relatively large theta13 and nearly maximal theta23 from the approximate S3 symmetry of lepton mass matrices
• Universal Texture of Quark and Lepton Mass Matrices and a Discrete Symmetry Z_3
• Neutrino Mass Sum-rules in Flavor Symmetry Models
• The $S_3$ flavour symmetry: Neutrino masses and mixings
• The breaking of the flavour permutational symmetry: Mass textures and the CKM matrix
• The breaking of the flavour permutational symmetry: Mass textures and the CKM matrix
• Broken S_3 Flavor Symmetry of Leptons and Quarks: Mass Spectra and Flavor Mixing Patterns
• The Breaking of Subnuclear Democracy as the Origin of Flavour Mixing
• Democratic Mass Matrices from Broken $O(3{)}_L\times O(3{)}_R$ Flavor Symmetry
• Broken S3 Symmetry in the Neutrino Mass Matrix and Non-Zero theta_{13}
• Flavor Mass and Mixing and S_3 Symmetry -- An S_3 Invariant Model Reasonable to All --
• Democratic Neutrino Mixing Reexamined
• Universal 2-3 symmetry
• Implications of the Quark Mass Hierarchy on Flavor Mixings
• Predicting Vckm with Universal Strength of Yukawa Couplings
• Are lepton flavor mixings in the democratic mass matrix stable against quantum corrections?
• The Symmetry behind Extended Flavour Democracy and Large Leptonic Mixing
• Flavor Democracy and Type-II Seesaw Realization of Bilarge Neutrino Mixing
• Generalized Hidden ${\mathcal{Z}}_2$ Symmetry of Neutrino Mixing
• Addressing Neutrino Mixing Models with DUNE and T2HK
• Predictivity of Neutrino Mass Sum Rules
• Discrete symmetries and mixing of Dirac neutrinos
• The breaking of flavor democracy in the quark sector
• Naturally perturbed S${}_3$ neutrinos
• Hierarchical majorana neutrinos from democratic mass matrices
• Broken $S_{3\mathrm{L}}^{}\times S_{3\mathrm{R}}^{}$ Flavor Symmetry and Leptonic CP Violation
• Review: Long-baseline oscillation experiments as a tool to probe High Energy Models

Cited by in corpus (8)

• Flavor structures of charged fermions and massive neutrinos
• B-L Model with ${\mathbf{S}}_3$ Symmetry: Nearest Neighbor Interaction Textures and Broken $\mu \leftrightarrow \tau$ Symmetry
• A non-renormalizable neutrino mass model with ${\mathbf{S}}_3\otimes {\mathbf{Z}}_2$ symmetry
• Breaking flavor democracy with symmetric perturbations
• Broken Democracy with Intermediate ${\mathbb{S}}_2\times {\mathbb{S}}_2$ Residual Symmetry and Random Perturbations
• A lepton model with nearly Cobimaximal mixing
• A comparative study between the modified Fritzsch and nearest neighbor interaction textures
• Scalar and gauge sectors in the 3-Higgs Doublet Model under the S3-symmetry