scholarly journals AN ANALYTICAL TREATMENT OF THE NEUTRINO MASSES AND MIXINGS

2013 ◽  
Vol 28 (39) ◽  
pp. 1350184
Author(s):  
RENATA JORA ◽  
JOSEPH SCHECHTER ◽  
M. NAEEM SHAHID
Keyword(s):  
Cp Violation ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Analytical Treatment ◽  
Unit Matrix ◽  
Mixing Matrix ◽  
Analytical Formulas ◽  
Neutrino Masses And Mixings

We obtain analytical formulas which connect the neutrino masses and the leptonic mixing matrix with the entries in the mass matrix for the approximation in which the charged lepton mixing matrix is the unit matrix. We also extract the CP violation phase and determine the conditions in which this is present.

scholarly journals NEUTRINO MIXING IN A DEMOCRATIC SEESAW MASS MATRIX MODEL

1996 ◽  
Vol 11 (36) ◽  
pp. 2849-2859 ◽  
Author(s):  
YOSHIO KOIDE
Keyword(s):  
Matrix Model ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Atmospheric Neutrino ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Unit Matrix ◽  
Up Quark ◽  
Type Mass ◽  
Neutrino Masses And Mixings

On the basis of a seesaw-type mass matrix model for quarks and leptons, [Formula: see text] where mL∝mR are universal for f=u, d, v and e (up-quark, downquark, neutrino and charged lepton sectors respectively), and MF has a form [(unit matrix)+(democratic-type matrix)], neutrino masses and mixings are investigated. We try to understand a large vµ−vτ mixing, i.e. sin2 2θ23~1, with mv1 ≪ mv2~mv3, which has been suggested by the atmospheric neutrino data.

scholarly journals CP violation and neutrino masses and mixings from quark mass hierarchies

2007 ◽  
Vol 2007 (12) ◽  
pp. 030-030 ◽  
Author(s):  
Wilfried Buchmüller ◽  
Laura Covi ◽  
David Emmanuel-Costa ◽  
Sören Wiesenfeldt
Keyword(s):  
Cp Violation ◽  
Quark Mass ◽  
Neutrino Masses ◽  
Neutrino Masses And Mixings

CP Violation in SU(3) × U(1) Electroweak Model

1997 ◽  
Vol 12 (24) ◽  
pp. 4411-4424 ◽  
Author(s):  
Tae Hoon Lee ◽  
Dae Sung Hwang
Keyword(s):  
Cp Violation ◽  
Mass Matrix ◽  
Neutral Current ◽  
Tree Level ◽  
Additional Contribution ◽  
Matrix Elements ◽  
Mixing Angle ◽  
Mixing Matrix ◽  
Electroweak Model ◽  
New Phase

We study the charged and the neutral current interactions of quarks in an SU (3)L × U (1)X electroweak model. Based on the assumption that u-type quarks coincide with their mass eigenstates, we obtain a new mixing angle θ′ and another CP violating phase δ′ in the extra heavy quark sector besides the usual Kobayashi–Maskawa mixing matrix. This new phase δ′ does not effect a change in the mass matrix elements of the [Formula: see text] systems when θ′ is small, but extra heavy quarks and gauge bosons give rise to additional contribution to the real part of the off-diagonal mass matrix elements and then the CP violation parameter ε is modified. By requiring that the tree level FCNC does not have an important effect on the [Formula: see text] and [Formula: see text] mixings in this model, we obtain a new lower bound on the mass of the extra heavy neutral gauge boson as 1.8 TeV.

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 Relating lepton mixing angles with lepton mass hierarchy

2016 ◽  
Vol 31 (04n05) ◽  
pp. 1650002
Author(s):  
Debasish Borah
Keyword(s):  
Neutrino Mass ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Mass Hierarchy ◽  
Mixing Angle ◽  
Mixing Angles ◽  
Mass Matrices ◽  
Model Independent ◽  
The Difference

We revisit the possibility of relating lepton mixing angles with lepton mass hierarchies in a model-independent way. Guided by the existence of such relations in the quark sector, we first consider all the mixing angles, both in charged lepton and neutrino sectors to be related to the respective mass ratios. This allows us to calculate the leptonic mixing angles observed in neutrino oscillations as functions of the lightest neutrino mass. We show that for both normal and inverted hierarchical neutrino masses, this scenario does not give rise to correct leptonic mixing angles. We then show that correct leptonic mixing angles can be generated with normal hierarchical neutrino masses if the relation between mixing angle and mass ratio is restricted to 1–2 and 1–3 mixing in both charged lepton and neutrino sectors leaving the 2–3 mixing angles as free parameters. We then restrict the lightest neutrino mass as well as the difference between 2–3 mixing angles in charged lepton and neutrino sectors from the requirement of producing correct leptonic mixing angles. We constrain the lightest neutrino mass to be around 0.002 eV and leptonic Dirac CP phase [Formula: see text] such that [Formula: see text]. We also construct the leptonic mass matrices in terms of 2–3 mixing angles and lightest neutrino mass and briefly comment on the possibility of realizing texture zeros in the neutrino mass matrix.

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 Charged Lepton Masses as a Possible CPV Source

2021 ◽  
Vol 8 (2) ◽  
pp. 161-168
Author(s):  
O. Félix-Beltrán ◽  
J. E. Barradas-Guevara J. E. Barradas-Guevara ◽  
F. González-Canales
Keyword(s):  
Cp Violation ◽  
Neutrino Oscillation ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Independent Study ◽  
Double Beta Decay ◽  
Flavor Mixing ◽  
Minimum Number ◽  
Two Phases ◽  
Charged Leptons

We realize a model-independent study of the so-called Tri-Bi-Maximal pattern of leptonic flavor mixing. Different charged lepton mass matrix textures are studied. In particular, we are interested in those textures with a minimum number of parameters and that are able to reproduce the current experimental data on neutrino oscillation. The textures studied here form an equivalent class with two texture zeros. We obtain a Tri-Bi-Maximal pattern deviation in terms of the charged leptons masses, leading to a reactor angle and three CP violation phases non-zero. These lastest are one CP violation phase Dirac-like and two phases Majorana-like. Also, we can test the phenomenological implications of the numerical values obtained for the mixing angles and CP violation phases, on the neutrinoless double beta decay, and in the present and upcoming experiments on long-base neutrino oscillation, such as T2K, NOvA, and DUNE.

scholarly journals CP violation in the lepton sector and implications for leptogenesis

2018 ◽  
Vol 33 (05n06) ◽  
pp. 1842006 ◽  
Author(s):  
C. Hagedorn ◽  
R. N. Mohapatra ◽  
E. Molinaro ◽  
C. C. Nishi ◽  
S. T. Petcov
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Low Energy ◽  
Current Status ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Lepton Sector ◽  
The Standard Model ◽  
Mixing Matrix ◽  
Cp Symmetry

We review the current status of the data on neutrino masses and lepton mixing and the prospects for measuring the CP-violating phases in the lepton sector. The possible connection between low energy CP violation encoded in the Dirac and Majorana phases of the Pontecorvo–Maki–Nakagawa–Sakata mixing matrix and successful leptogenesis is emphasized in the context of seesaw extensions of the Standard Model with a flavor symmetry [Formula: see text] (and CP symmetry).

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 Perturbative bottom-up approach for neutrino mass matrix in light of large θ13 and role of lightest neutrino mass

2014 ◽  
Vol 29 (22) ◽  
pp. 1450113 ◽  
Author(s):  
Rupak Dutta ◽  
Upender Ch ◽  
Anjan K. Giri ◽  
Narendra Sahu
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Tree Level ◽  
Neutrino Masses ◽  
Bottom Up ◽  
Mixing Angles ◽  
Atmospheric Mass ◽  
Neutrino Masses And Mixings

We discuss the role of lightest neutrino mass (m0) in the neutrino mass matrix, defined in a flavor basis, through a bottom-up approach using the current neutrino oscillation data. We find that if m0 < 10-3 eV , then the deviation δMν in the neutrino mass matrix from a tree-level, say tribimaximal neutrino mass matrix, does not depend on m0. As a result δMν's are exactly predicted in terms of the experimentally determined quantities such as solar and atmospheric mass squared differences and the mixing angles. On the other hand for m0 ≳10-3 eV , δMν strongly depends on m0 and hence cannot be determined within the knowledge of oscillation parameters alone. In this limit, we provide an exponential parametrization for δMν for all values of m0 such that it can factorize the m0 dependency of δMν from rest of the oscillation parameters. This helps us in finding δMν as a function of the solar and atmospheric mass squared differences and the mixing angles for all values of m0. We use this information to build up a model of neutrino masses and mixings in a top-down scenario which can predict large θ13 perturbatively.

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