scholarly journals THE MINIMAL TYPE-II SEESAW MODEL AND FLAVOR-DEPENDENT LEPTOGENESIS

2008 ◽  
Vol 23 (21) ◽  
pp. 3412-3415
Author(s):  
SHU LUO ◽  
ZHI-ZHONG XING
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Baryon Number ◽  
Majorana Neutrino ◽  
Type Ii ◽  
Neutrino Mixing ◽  
Seesaw Model ◽  
Mixing Matrix ◽  
Current Experimental Data ◽  
Minimal Type

Current experimental data allow the zero value for one neutrino mass, either m1 = 0 or m3 = 0. This observation implies that a realistic neutrino mass texture can be established by starting from the limit (a) m1 = m2 = 0 and m3 ≠ 0 or (b) m1 = m2 ≠ 0 and m3 = 0. In both cases, we may introduce a particular perturbation which ensures the resultant neutrino mixing matrix to be the tri-bimaximal mixing pattern or its viable variations. We find that it is natural to incorporate this kind of neutrino mass matrix in the minimal Type-II seesaw model with only one heavy right-handed Majorana neutrino N. We show that it is possible to account for the cosmological baryon number asymmetry in the m3 = 0 case via thermal leptogenesis, in which the CP-violating asymmetry of N decays is attributed to the electron flavor.

scholarly journals NEUTRINO MASSES, LEPTON FLAVOR MIXING AND LEPTOGENESIS IN THE MINIMAL SEESAW MODEL

2007 ◽  
Vol 16 (01) ◽  
pp. 1-50 ◽  
Author(s):  
WAN-LEI GUO ◽  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Seesaw Model ◽  
Flavor Mixing ◽  
Majorana Neutrinos

We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as μ→e+γ, are also discussed in the supersymmetric extension of the MSM.

Remark on Majorana CP phases in neutrino mixing and leptogenesis

2014 ◽  
Vol 29 (16) ◽  
pp. 1450087
Author(s):  
Teruyuki Kitabayashi ◽  
Naoto Koizumi
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Half Life ◽  
Neutrinoless Double Beta Decay ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Mixing ◽  
Seesaw Model ◽  
Mixing Matrix ◽  
Majorana Neutrino Mass

We estimate Majorana CP phases for a simple flavor neutrino mixing matrix which has been reported by Qu and Ma. Sizes of Majorana CP phases are evaluated in the study of the neutrinoless double beta decay and a particular leptogenesis scenario. We find the dependence of the physically relevant Majorana CP phase on the mass of lightest right-handed neutrino in the minimal seesaw model and the effective Majorana neutrino mass which is related with the half-life of the neutrinoless double beta decay.

scholarly journals TeV-SCALE TYPE-II SEESAW MODELS AND POSSIBLE COLLIDER SIGNATURES

2008 ◽  
Vol 23 (21) ◽  
pp. 3420-3424 ◽  
Author(s):  
WEI CHAO ◽  
SHU LUO ◽  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Natural Extension ◽  
Simple Type ◽  
Type Ii ◽  
Neutrino Mixing ◽  
Long Baseline ◽  
Majorana Neutrinos ◽  
Mixing Matrix ◽  
The Right

A natural extension of the standard model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6×6 neutrino mass matrix. We show that three light Majorana neutrinos (i.e., the mass eigenstates of νe, νμ and ντ) are exactly massless, if and only if [Formula: see text] exactly holds in this seesaw model. We propose three simple Type-II seesaw scenarios with broken A4 × U(1)x flavor symmetry to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the 3 × 3 neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.

scholarly journals Investigating the Hybrid Textures of Neutrino Mass Matrix for Near Maximal Atmospheric Neutrino Mixing

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Madan Singh
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Atmospheric Neutrino ◽  
Zero Element ◽  
Majorana Neutrino ◽  
Neutrino Mixing ◽  
Mixing Angle ◽  
The Comparative Study ◽  
Reactor Mixing ◽  
Majorana Neutrino Mass

We have studied that the implication of a large value of the effective Majorana neutrino mass in case of neutrino mass matrices has either two equal elements and one zero element (popularly known as hybrid texture) or two equal cofactors and one zero minor (popularly known as inverse hybrid texture) in the flavor basis. In each of these cases, four out of sixty phenomenologically possible patterns predict near maximal atmospheric neutrino mixing angle in the limit of large effective Majorana neutrino mass. This feature remains irrespective of the experimental data on solar and reactor mixing angles. In addition, we have also performed the comparative study of all the viable cases of hybrid and inverse hybrid textures at 3σ CL.

scholarly journals IS Ue3 REALLY RELATED TO THE SOLAR NEUTRINO SOLUTIONS?

2000 ◽  
Vol 15 (37) ◽  
pp. 2257-2263
Author(s):  
N. HABA ◽  
TOMOHARU SUZUKI
Keyword(s):  
Physical Parameter ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Solar Neutrino ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Lepton Flavor ◽  
Flavor Mixing ◽  
Mixing Matrix ◽  
Majorana Neutrino Mass

It is important to measure Ue3 in the lepton flavor mixing matrix in order to understand the structure of Majorana neutrino mass matrix. Recently it is conjectured that the measurement of Ue3 would discriminate one solution among various solar neutrino ones provided that the three mass eigenvalues of neutrinos have the relation m1≪m2≪m3 or m1~m2≪m3. In this letter we show that this conjecture is rather restrictive and the relation [Formula: see text] is derived by a nontrivial assumption and Ue3 cannot discriminate among solar neutrino oscillation solutions without the information on another physical parameter.

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 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 THE MINIMAL TYPE-I SEESAW MODEL AND FLAVOR-DEPENDENT LEPTOGENESIS

2008 ◽  
Vol 23 (21) ◽  
pp. 3403-3407 ◽  
Author(s):  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Yukawa Coupling ◽  
Baryon Number ◽  
Type I ◽  
Neutrino Mixing ◽  
Coupling Matrix ◽  
Seesaw Model ◽  
Majorana Neutrinos ◽  
Minimal Type ◽  
Baryon Number Asymmetry

In this talk, we first give a brief review of the so-called minimal seesaw models and then concentrate on the minimal type-I seesaw model with two almost degenerate right-handed Majorana neutrinos of [Formula: see text]. A specific texture of the neutrino Yukawa coupling matrix is proposed to achieve the nearly tri-bimaximal neutrino mixing pattern. This ansatz predicts (1) θ23 = π/4, |δ| = π/2 and sin 2θ12 = (1 − 2tan2θ13)/3 in the m1 = 0 case; and (2) θ23 = π/4 and θ13 = 8 = 0 in the m3 = 0 case. In both cases, the cosmological baryon number asymmetry can be explained via the resonant leptogenesis mechanism. Finally, we demonstrate the significance of flavor-dependent effects in our leptogenesis scenario.

BIPAIR NEUTRINO MIXING AND LEPTOGENESIS

2013 ◽  
Vol 28 (07) ◽  
pp. 1350016 ◽  
Author(s):  
TERUYUKI KITABAYASHI
Keyword(s):  
Mass Matrix ◽  
Baryon Number ◽  
Neutrino Mixing ◽  
Lepton Asymmetry ◽  
Mixing Angle ◽  
Dirac Mass ◽  
Seesaw Model ◽  
Reactor Neutrino ◽  
The Universe

We estimate the baryon–photon ratio in the Universe via the leptogenesis scenario in the framework of the minimal seesaw model with a minimally modified bipair neutrino mixing. We assume that one of the elements of the 3 × 2 Dirac mass matrix mD is exactly zero. It turns out that the lepton asymmetry as well as baryon number of the Universe definitely depends on the reactor neutrino mixing angle in the cases of (mD)11 = 0 and (mD)12 = 0. The allowed region of the Majorana CP phase is separated into three regions related to the assumption of either (mD)11 = 0, (mD)21, 31 = 0 or (mD)12 = 0.

scholarly journals The Texture One-Zero Neutrino Mass Matrix with Vanishing Trace

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Madan Singh
Keyword(s):  
Experimental Data ◽  
Neutrino Mass ◽  
Confidence Level ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Neutrino Mass Matrix ◽  
Current Experimental Data ◽  
The One ◽  
Zero Sum ◽  
Majorana Neutrino Mass

In the light of latest neutrino oscillation data, we have investigated the one-zero Majorana neutrino mass matrix Mν with zero sum condition of mass eigenvalues in the flavor basis, where charged lepton mass matrix is diagonal. Among the six possible one-zero cases, it is found that only five can survive the current experimental data, while case with (1, 1) vanishing element of Mν is ruled out, if zero trace condition is imposed at 3σ confidence level (CL). Numerical and some approximate analytical results are presented.

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