scholarly journals NONZERO θ13 AND NEUTRINO MASSES FROM MODIFIED NEUTRINO MIXING MATRIX

2012 ◽  
Vol 27 (17) ◽  
pp. 1250091 ◽  
Author(s):  
ASAN DAMANIK
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Daya Bay ◽  
Neutrino Mixing ◽  
Inverted Hierarchy ◽  
Solar Mass ◽  
Double Chooz ◽  
Mass Matrices ◽  
Mixing Matrix

The nonzero and relatively large θ13 have been reported by Daya Bay, T2K, MINOS and Double Chooz Collaborations. In order to accommodate the nonzero θ13, we modified the tribimaximal (TB), bimaxima (BM) and democratic (DC) neutrino mixing matrices. From three modified neutrino mixing matrices, two of them (the modified BM and DC mixing matrices) can give nonzero θ13 which is compatible with the result of the Daya Bay and T2K experiments. The modified TB neutrino mixing matrix predicts the value of θ13 which is greater than the upper bound value of the latest experimental results. By using the modified neutrino mixing matrices and imposing an additional assumption that neutrino mass matrices have two zeros texture, we then obtain the neutrino mass in normal hierarchy when (Mν)22 = (Mν)33 = 0 for the neutrino mass matrix from the modified TB neutrino mixing matrix and (Mν)11 = (Mν)13 = 0 for the neutrino mass matrix from the modified DC neutrino mixing matrix. For these two patterns of neutrino mass matrices, either the atmospheric mass squared difference or the solar mass squared difference can be obtained, but not both of them simultaneously. From four patterns of two zeros texture to be considered on the obtained neutrino mass matrix from the modified BM neutrino mixing matrix, none of them can correctly predict the neutrino mass spectrum (normal or inverted hierarchy).

scholarly journals A discrete anatomy of the neutrino mass matrix

2014 ◽  
Vol 29 (33) ◽  
pp. 1450179
Author(s):  
G. K. Leontaris ◽  
N. D. Vlachos
Keyword(s):  
Finite Group ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Current Data ◽  
Neutrino Mass Matrix ◽  
Linear Combinations ◽  
Mixing Angle ◽  
Mass Matrices ◽  
Mixing Matrix ◽  
Charged Leptons

We investigate the possibility of expressing the charged leptons and neutrino mass matrices as linear combinations of elements of a single finite group. Constraints imposed on the resulting mixing matrix by current data restrict the group types, but allow a nonzero value for the θ13 mixing angle.

scholarly journals PERTURBED INVARIANT UNDER A CYCLIC PERMUTATION WITH TRACE OF NEUTRINO MASS MATRIX REMAIN CONSTANT

2011 ◽  
Vol 26 (08) ◽  
pp. 567-574 ◽  
Author(s):  
ASAN DAMANIK
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Cyclic Permutation ◽  
Neutrino Mass Matrix ◽  
Neutrino Masses ◽  
Inverted Hierarchy ◽  
Seesaw Mechanism ◽  
Mixing Parameters ◽  
Difference Formula ◽  
Mass Matrices

We construct a neutrino mass matrix Mν via a seesaw mechanism with perturbed invariant under a cyclic permutation by introducing a parameter δ into the diagonal elements of Mν with the assumption that trace of the perturbed Mν is equal to trace of the unperturbed Mν. We found that the perturbed neutrino mass matrices Mν can predict the mass-squared difference [Formula: see text] with the possible hierarchy of neutrino mass is normal or inverted hierarchy. By using the advantages of the mass-squared differences and mixing parameters data from neutrino oscillation experiments, we then have neutrino masses in inverted hierarchy with masses: |m1| = 0.101023 eV , |m2| = 0.101428 eV and |m3| = 0.084413 eV .

SYMMETRIES OF NEUTRINO MIXING

2003 ◽  
Vol 18 (22) ◽  
pp. 3957-3970 ◽  
Author(s):  
P. F. HARRISON ◽  
W. G. SCOTT
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Neutrino Mixing ◽  
Natural Representation ◽  
Induced Representation ◽  
Group Matrix ◽  
Class Operator ◽  
Mixing Matrix ◽  
Mass Basis

Encouraged by the phenomenological success of the tri-bimaximal hypothesis, we postulate that the neutrino mass matrix in the lepton flavour basis is an S3 group matrix in the natural representation of S3. This immediately requires one neutrino to be trimaximally mixed, as suggested by the solar neutrino data. We go on to postulate that the charged-lepton mass matrix in the neutrino mass-basis is an S3 class matrix in the natural representation of the S3 class-algebra, leading to exact tri-bimaximal mixing which is compatible with data overall. The above two postulates are mutually consistent, and imply that the neutrino mass matrix in the flavour basis is an S3⊃S2 class operator, in the natural representation of the S3 group (the S2 being associated with mu-tau interchange). Thus the tri-bimaximal mixing matrix is seen to be closely related to the S3 group characters, and may be properly regarded as simply the table of induction coefficients for the [2]×[1]=[3]+[21] induced representation of S3.

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 TETRAHEDRAL FAMILY SYMMETRY AND THE NEUTRINO MIXING MATRIX

2005 ◽  
Vol 20 (34) ◽  
pp. 2601-2605 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Neutrino Mixing ◽  
Symmetry Limit ◽  
Family Symmetry ◽  
Seesaw Mechanism ◽  
Mixing Angles ◽  
Mixing Matrix ◽  
Natural Symmetry

In a new application of the discrete non-Abelian symmetry A4 using the canonical seesaw mechanism, a three-parameter form of the neutrino mass matrix is derived. It predicts the following mixing angles for neutrino oscillations: θ13=0, sin 2θ23=1/2, and sin 2θ12 close, but not exactly equal to 1/3, in one natural symmetry limit.

Neutrino masses from modified bimaximal mixing

2015 ◽  
Vol 30 (32) ◽  
pp. 1550169
Author(s):  
Asan Damanik
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Mass Difference ◽  
Atmospheric Neutrino ◽  
Double Beta Decay ◽  
Neutrino Mass Matrix ◽  
Experimental Results ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Matrix

The bimaximal (BM) neutrino mixing matrix was formulated in order to accommodate the data of the experimental results which indicate that both solar and atmospheric neutrino oscillation in vacuum are near maximal. But, after the T2K and Daya Bay Collaborations reported that the mixing angle [Formula: see text] is nonzero and relatively large, many authors have modified the neutrino mixing matrix in order to accommodate experimental data. We modified the BM mixing matrix by introducing a simple perturbation matrix into BM mixing matrix. The modified BM mixing matrix can proceed the mixing angles which are compatible with the global fit analysis data and by imposing the [Formula: see text]–[Formula: see text] symmetry into mass matrix from modified BM, we have the neutrino mass in normal hierarchy (NH): [Formula: see text]. Using the neutrino masses that obtained from neutrino mass matrix in the scheme of modified BM and imposing the constraint exact [Formula: see text] symmetry into neutrino mass matrix, we cannot have compatible squared-mass differences for both [Formula: see text] and [Formula: see text] as dictated by experimental results. In order to proceed the neutrino masses that can predict correctly the squared-mass difference, we introduce a small parameter [Formula: see text] into neutrino mass matrix. The obtained neutrino masses are in agreement with the squared-mass difference as dictated by experimental results. The predicted neutrino effective mass: [Formula: see text] in this paper can be tested in the future neutrinoless double beta decay.

scholarly journals TRIBIMAXIMAL MIXING IN NEUTRINO MASS MATRICES WITH TEXTURE ZEROS OR VANISHING MINORS

2011 ◽  
Vol 26 (07) ◽  
pp. 501-514 ◽  
Author(s):  
S. DEV ◽  
SHIVANI GUPTA ◽  
RADHA RAMAN GAUTAM
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Mass Scale ◽  
Neutrino Mass Matrix ◽  
Seesaw Mechanism ◽  
Majorana Mass ◽  
Absolute Mass ◽  
Mass Matrices ◽  
The One ◽  
The Right

We study the existence of one/two texture zeros or one/two vanishing minors in the neutrino mass matrix with μτ symmetry. In the basis where the charged lepton mass matrix and the Dirac neutrino mass matrix are diagonal, the one/two zeros or one/two vanishing minors on the right-handed Majorana mass matrix having μτ symmetry will propagate via seesaw mechanism as one/two vanishing minors or one/two texture zeros in the neutrino mass matrix with μτ symmetry respectively. It is found that only five such texture structures of the neutrino mass matrix are phenomenologically viable. For tribimaximal mixing, these texture structures reduce the number of free parameters to one. Interesting predictions are obtained for the effective Majorana mass Mee, the absolute mass scale and the Majorana-type CP violating phases.

scholarly journals CHARGED LEPTON CORRECTION TO TRI-BIMAXIMAL LEPTON MIXING AND ITS IMPLICATIONS TO NEUTRINO PHENOMENOLOGY

2013 ◽  
Vol 28 (31) ◽  
pp. 1350131 ◽  
Author(s):  
SRINU GOLLU ◽  
K. N. DEEPTHI ◽  
R. MOHANTA
Keyword(s):  
Charged Lepton ◽  
Daya Bay ◽  
Neutrino Mixing ◽  
Mixing Angle ◽  
Quark Sector ◽  
Mass Matrices ◽  
Reactor Neutrino ◽  
Mixing Matrix ◽  
Neutrino Experiments ◽  
Reactor Mixing

The recent results from Daya Bay and RENO reactor neutrino experiments have firmly established that the smallest reactor mixing angle θ13 is nonvanishing at the 5 σ level, with a relatively large value, i.e. θ13 ≈ 9°. Using the fact that the neutrino mixing matrix can be represented as [Formula: see text], where Ul and Uν result from the diagonalization of the charged lepton and neutrino mass matrices and Pν is a diagonal matrix containing the Majorana phases and assuming the tri-bimaximal (TBM) form for Uν, we investigate the possibility of accounting for the large reactor mixing angle due to the corrections of the charged lepton mixing matrix. The form of Ul is assumed to be that of CKM mixing matrix of the quark sector. We find that with this modification it is possible to accommodate the large observed reactor mixing angle θ13. We also study the implications of such corrections on the other phenomenological observables.

scholarly journals Hybrid textures of neutrino mass matrix under the lamppost of latest neutrino and cosmology data

2016 ◽  
Vol 31 (06) ◽  
pp. 1650008 ◽  
Author(s):  
Rupam Kalita ◽  
Debasish Borah
Keyword(s):  
Neutrino Mass ◽  
Parameter Space ◽  
Mass Formula ◽  
Mass Matrix ◽  
Zero Element ◽  
Baryon Asymmetry ◽  
Double Beta Decay ◽  
Neutrino Mass Matrix ◽  
Type I ◽  
Mass Matrices

In this paper, we study all possible neutrino mass matrices with one zero element and two equal nonzero elements, known as hybrid texture neutrino mass matrices. In the diagonal charged lepton basis, we consider 39 such possible cases which are consistent with the latest neutrino data. Using the two constraints on neutrino mass matrix elements imposed by hybrid textures, we numerically evaluate the neutrino parameters like the lightest neutrino mass [Formula: see text], one Dirac CP phase [Formula: see text] and two Majorana CP phases [Formula: see text], [Formula: see text] by using the global fit [Formula: see text] values of three mixing angles and two mass squared differences. We then constrain this parameter space by using the cosmological upper bound on the sum of absolute neutrino masses given by Planck experiment. We also calculate the effective neutrino mass [Formula: see text] for this region of parameter space which can have relevance in future neutrinoless double beta decay experiments. We finally discriminate between these hybrid texture mass matrices from the requirement of producing correct baryon asymmetry through type I seesaw leptogenesis. We also constrain the light neutrino parameter space as well as the lightest right-handed neutrino mass from the constraint on baryon asymmetry of the Universe from Planck experiment.

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