scholarly journals GENERALIZED FRIEDBERG-LEE MODEL FOR NEUTRINO MASSES AND LEPTONIC CP VIOLATION FROM μ-τ SYMMETRY BREAKING

2008 ◽  
Vol 23 (21) ◽  
pp. 3384-3387 ◽  
Author(s):  
ZHI-ZHONG XING ◽  
HE ZHANG ◽  
SHUN ZHOU
Keyword(s):  
Cp Violation ◽  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mass Model ◽  
Lee Model ◽  
Massive Neutrinos ◽  
Free Parameters

Assuming the Majorana nature of massive neutrinos, we generalize the Friedberg-Lee neutrino mass model to include CP violation in the neutrino mass matrix Mν. The most general case with all the free parameters of Mν being complex is discussed. We show that a favorable neutrino mixing pattern (with θ12 ≈ 35.3°, θ23 = 45°, θ13 ≠ 0° and δ = 90°) can naturally be derived from Mν, if it has an approximate or softly-broken μ-τ symmetry. We also point out a different way to obtain the nearly tri-bimaximal neutrino mixing pattern with δ = 0° and non-vanishing Majorana phases.

WHAT DOES μ - τ SYMMETRY IMPLY ABOUT LEPTONIC CP VIOLATION?

2007 ◽  
Vol 16 (05) ◽  
pp. 1373-1381 ◽  
Author(s):  
TEPPEI BABA
Keyword(s):  
Experimental Data ◽  
Cp Violation ◽  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Mass Difference ◽  
Atmospheric Neutrino ◽  
Symmetric Part ◽  
Neutrino Mixing ◽  
Mixing Angles

The μ - τ symmetry can reproduce the consistent results with experimental data of θ13, and θ23 (θ13, and θ23 respectively denote the νe - ντ, and νμ - ντ, mixing angles). However, we can not address the issue of the leptonic CP violation in μ - τ symmetric models. So we add the μ - τ symmetry breaking part to include the CP violation. We characterize leptonic CP violation in terms of three phases, where one is conventional phase δ and others are additional phases ρ and γ. These δ, ρ and γ are, respectively, the phases of νe - ντ, νe - νμ and νμ - ντ mixings. The ρ and γ are redundant but the effect of ρ remains in the leptonic CP violation which is characterized by δ + ρ. The δ arises from the μ - τ symmetry breaking part of the Meμ and Meτ while ρ arises from of μ - τ symmetric part of the Meμ and Meτ, where Mij stands for ij (i,j = e,μ,τ) element of M(= [Formula: see text] for Mν being a flavor neutrino mass matrix). Moreover, θ23 can be exactly estimated to be: [Formula: see text] ( sin θ ∝ sin θ13 cos (δ + ρ)[Formula: see text], sin ϕ ∝ Mμμ - Mττ, where [Formula: see text] is the solar neutrino mass difference squared). The conditions of maximal atmospheric neutrino mixing are given by [Formula: see text] and Mμμ = Mττ,which indicate maximal Dirac CP violation.

scholarly journals Neutrino masses in an $$SU(4)\otimes U(1)$$-electroweak model with a scalar decuplet

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
N. Anh Ky ◽  
N. T. Hong Van ◽  
D. Nguyen Dinh ◽  
P. Quang Van
Keyword(s):  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Particle Physics ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Coupling Coefficients ◽  
Mass Model ◽  
Yukawa Couplings ◽  
Distribution Shape ◽  
Independent Distribution

Abstract A neutrino mass model is suggested within an $$SU(4)\otimes U(1)$$SU(4)⊗U(1)-electroweak theory. The smallness of neutrino masses can be guaranteed by a seesaw mechanism realized through Yukawa couplings to a scalar SU(4)-decuplet. In this scheme the light active neutrinos are accompanied by heavy neutrinos, which may have masses at different scales, including those within eV–MeV scales investigated quite intensively in both particle physics and astrophysics/cosmology. The flavour neutrinos are superpositions of light neutrinos and a small fraction of heavy neutrinos with the mixing to be determined by the model’s parameters (Yukawa coupling coefficients or symmetry breaking scales). The distribution shape of the Yukawa couplings can be visualized via a model-independent distribution of the neutrino mass matrix elements derived by using the current experimental data. The absolute values of these Yukawa couplings are able to be determined if the symmetry breaking scales are known, and vice versa. With reference to several current and near future experiments, detectable bounds of these heavy neutrinos at different mass scales are discussed and estimated.

scholarly journals $$3+1$$ active–sterile neutrino mixing in $$B-L$$ model with $$S_{3}{\times Z_4\times Z_2}$$ symmetry for normal neutrino mass ordering

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
V. V. Vien
Keyword(s):  
Neutrino Mass ◽  
Sterile Neutrino ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Yukawa Interaction ◽  
Neutrino Mixing ◽  
Normal Ordering ◽  
Mixing Angles ◽  
Active Mixing ◽  
Best Fit

AbstractWe propose a non-renormalizable $$B-L$$ B - L model with $$S_{3}{\times Z_4\times Z_2}$$ S 3 × Z 4 × Z 2 symmetry which successfully accommodates the current active–sterile neutrino mixing in $$3+1$$ 3 + 1 scheme. The $$S_3$$ S 3 flavor symmetry is supplemented by $$Z_4\otimes Z_2$$ Z 4 ⊗ Z 2 symmetry to consolidate the Yukawa interaction of the model. The presence of $$S_3\otimes Z_4\otimes Z_2$$ S 3 ⊗ Z 4 ⊗ Z 2 flavour symmetry plays an important role in generating the desired structure of the neutrino mass matrix. The model can reproduce the recent observed active-neutrino neutrino oscillation data for normal ordering in which two sterile–active mixing angles $$\theta _{14, 24}$$ θ 14 , 24 get the best-fit values and the obtained values of $$\theta _{34}, \delta _{14}, \delta _{14}$$ θ 34 , δ 14 , δ 14 , the sum of neutrino mass and the effective neutrino masses are within their currently allowed ranges.

scholarly journals Lepton mass and mixing in a neutrino mass model based onS4flavor symmetry

2016 ◽  
Vol 31 (09) ◽  
pp. 1650039 ◽  
Author(s):  
V. V. Vien
Keyword(s):  
Cp Violation ◽  
Neutrino Mass ◽  
Tree Level ◽  
Neutrino Mixing ◽  
Mass Model ◽  
Mixing Angles ◽  
Neutrino Sector ◽  
Neutrino Mass And Mixing ◽  
Model Based ◽  
Mixing Matrix

We study a neutrino mass model based on [Formula: see text] flavor symmetry which accommodates lepton mass, mixing with nonzero [Formula: see text] and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic neutrino mass and mixing pattern at the tree-level with renormalizable interactions. Indeed, the neutrinos get small masses from one [Formula: see text] doublet and two [Formula: see text] singlets in which one being in [Formula: see text] and the two others in [Formula: see text] under [Formula: see text] with both the breakings [Formula: see text] and [Formula: see text] are taken place in charged lepton sector and [Formula: see text] in neutrino sector. The model also gives a remarkable prediction of Dirac CP violation [Formula: see text] or [Formula: see text] in both the normal and inverted spectrum which is still missing in the neutrino mixing matrix. The relation between lepton mixing angles is also represented.

scholarly journals NEUTRINO OSCILLATIONS AND LEPTON FLAVOR MIXING

2001 ◽  
Vol 16 (33) ◽  
pp. 2169-2175 ◽  
Author(s):  
KYUNGSIK KANG ◽  
SIN KYU KANG ◽  
C. S. KIM ◽  
SUN MYONG KIM
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Input Constraints ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Invariance Violation ◽  
The Family ◽  
Flavor Mixing ◽  
Mixing Matrix

In view of the recent announcement on nonzero neutrino mass from Super-Kamiokande experiment, it would be very timely to investigate all the possible scenarios on masses and mixings of light neutrinos. Recently suggested mass matrix texture for the quark CKM mixing, which can be originated from the family permutation symmetry and its suitable breakings, is assumed for the neutrino mass matrix and determined by the four combinations of solar, atmospheric and LSND neutrino data and cosmological hot dark matter bound as input constraints. The charged-lepton mass matrix is assumed to be diagonal so that the neutrino mixing matrix can be identified directly as the lepton flavor mixing matrix and no CP invariance violation originates from the leptonic sector. The results favor hierarchical patterns for the neutrino masses, which follow from the case when the solar-atmospheric data is used.

scholarly journals Inverted neutrino mass hierarchy and mixing in the Zee-Babu model

2016 ◽  
Vol 25 (4) ◽  
pp. 291
Author(s):  
Vo Van Vien ◽  
Hoang Ngoc Long ◽  
Phan Ngoc Thu
Keyword(s):  
Cp Violation ◽  
Effective Mass ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Double Beta Decay ◽  
Recent Analysis ◽  
Neutrino Masses ◽  
Mass Hierarchy ◽  
Neutrino Mass Hierarchy

We show that the neutrino mass matrix of the Zee-Babu model isable to fit the recent data on neutrino masses and mixingwith non-zero $\theta_{13}$ in the inverted neutrino mass hierarchy. The results show that the Majorana  phases are equal to zero and the Dirac phase ($\de$) ispredicted to either $0$ or $\pi$, i. e, there is no CP violation in the Zee-Babu model at the two loop level. The effective mass governingneutrinoless double beta decay and the sum of neutrino masses areconsistent with the recent analysis.

scholarly journals STUDY OF LEPTONIC CP VIOLATION

2004 ◽  
Vol 19 (31) ◽  
pp. 5367-5375 ◽  
Author(s):  
S. NASRI ◽  
J. SCHECHTER ◽  
S. MOUSSA
Keyword(s):  
Cp Violation ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Grand Unification ◽  
Neutrino Masses

The "complementary" Ansatz, Tr (Mν)=0, where Mν is the prediagonal neutrino mass matrix, seems a plausible approximation for capturing in a self contained way some of the content of Grand Unification. We study its consequences in the form of relations between the neutrino masses and CP violation phases.

scholarly journals NEUTRINO MIXING AND THE DOUBLE TETRAHEDRAL GROUP

2013 ◽  
Vol 28 (29) ◽  
pp. 1350157 ◽  
Author(s):  
YONI BENTOV ◽  
A. ZEE
Keyword(s):  
Group Theory ◽  
Cp Violation ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Double Cover ◽  
Neutrino Mass Matrix ◽  
Two Dimensional ◽  
Neutrino Mixing ◽  
Mixing Matrix ◽  
Relevant Group

In the spirit of a previous study of the tetrahedral group T ≃A4, we discuss a minimalist scheme to derive the neutrino mixing matrix using the double tetrahedral group T′, the double cover of T. The new features are three distinct two-dimensional representations and complex Clebsch–Gordan coefficients, which can result in a geometric source of CP violation in the neutrino mass matrix. In an appendix, we derive explicitly the relevant group theory for the tetrahedral group T and its double cover T′.

scholarly journals Connecting leptonic CP violation, lightest neutrino mass and baryon asymmetry through type II seesaw

2015 ◽  
Vol 30 (09) ◽  
pp. 1550045 ◽  
Author(s):  
Rupam Kalita ◽  
Debasish Borah
Keyword(s):  
Cp Violation ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Baryon Asymmetry ◽  
Type I ◽  
Type Ii ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
The Universe ◽  
Mass Type

We study the possibility of connecting leptonic Dirac CP phase δ, lightest neutrino mass and baryon asymmetry of the universe within the framework of a model where both type I and type II seesaw mechanisms contribute to neutrino mass. Type I seesaw gives rise to Tri-Bimaximal (TBM) type neutrino mixing whereas type II seesaw acts as a correction in order to generate nonzero θ13. We derive the most general form of type II seesaw mass matrix which cannot only give rise to correct neutrino mixing angles but also can generate nontrivial value of δ. Considering both the cases where type II seesaw is subleading and is equally dominant compared to type I seesaw, we correlate the type II seesaw term with δ and lightest neutrino mass. We further constrain the Dirac CP phase δ and hence the type II seesaw mass matrix from the requirement of producing the observed baryon asymmetry through the mechanism of leptogenesis.

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