scholarly journals Cosmic Baryon Asymmetry in Different Neutrino Mass Models with Mixing Angles

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Ng. K. Francis
Keyword(s):  
Neutrino Mass ◽  
Baryon Asymmetry ◽  
Diagonal Form ◽  
Mixing Angles ◽  
Mass Matrices ◽  
Type Ia ◽  
Three Stages ◽  
Neutrino Mass Models ◽  
The Right ◽  
Right Order

We investigate the comparative studies of cosmological baryon asymmetry in different neutrino mass models with and withoutθ13by considering the three-diagonal form of Dirac neutrino mass matrices and the three aspects of leptogenesis, unflavoured, flavoured, and nonthermal. We found that the estimations of any models withθ13are consistent in all the three stages of calculations of leptogenesis and the results are better than the predictions of any models withoutθ13which are consistent in a piecemeal manner with the observational data in all the three stages of leptogenesis calculations. For the normal hierarchy of Type-IA with charged lepton matrix, model with and withoutθ13predicts inflaton mass required to produce the observed baryon asymmetry to beMϕ~2.2×1011 GeV andMϕ~3.6×1010 GeV, and the corresponding reheating temperatures areTR~4.86×106 GeV andTR~4.50×106 GeV respectively. These predictions are not in conflict with the gravitino problem which required the reheating temperature to be below107 GeV. And these values apply to the recent discovery of Higgs boson of mass~125 GeV. One can also have the right order of relic dark matter abundance only if the reheating temperature is bounded to below107 GeV.

scholarly journals RIGHT-HANDED MAJORANA NEUTRINO MASS MATRICES FOR GENERATING BIMAXIMAL MIXINGS IN DEGENERATE AND INVERTED MODELS OF NEUTRINOS

2003 ◽  
Vol 18 (05) ◽  
pp. 743-753 ◽  
Author(s):  
MAHADEV PATGIRI ◽  
N. NIMAI SINGH
Keyword(s):  
Neutrino Mass ◽  
Atmospheric Neutrino ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Diagonal Form ◽  
Left Handed ◽  
Mass Matrices ◽  
Neutrino Mass Models ◽  
The Right ◽  
Majorana Neutrino Mass

An attempt is made to generate the bimaximal mixings of the three species of neutrinos from the textures of the right-handed Majorana neutrino mass matrices. We extend our earlier work in this paper for the generation of the nearly degenerate as well as the inverted hierarchical models of the left-handed Majorana neutrino mass matrices using the non-diagonal textures of the right-handed Majorana neutrino mass matrices and the diagonal form of Dirac neutrino mass matrices, within the framework of the see-saw mechanism in a model independent way. Such Majorana neutrino mass models are important in explaining the recently reported result on the neutrinoless double beta decay (0νββ) experiment, together with the earlier established data on LMA MSW solar and atmospheric neutrino oscillations.

scholarly journals BIMAXIMAL MIXINGS FROM THE TEXTURE OF THE RIGHT-HANDED MAJORANA NEUTRINO MASS MATRIX

2002 ◽  
Vol 17 (25) ◽  
pp. 3629-3640 ◽  
Author(s):  
N. NIMAI SINGH ◽  
MAHADEV PATGIRI
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Atmospheric Neutrino ◽  
Majorana Neutrino ◽  
Neutrino Mass Matrix ◽  
Diagonal Form ◽  
Dirac Neutrino ◽  
Mass Matrices ◽  
The Right ◽  
Majorana Neutrino Mass

We study the origin of neutrino masses and mixing angles which can accommodate the LMA MSW solutions of the solar neutrino anomaly as well as the solution of the atmospheric neutrino problem, within the framework of the see-saw mechanism. We employ the diagonal form of the Dirac neutrino mass matrices with the physical masses as diagonal elements in the hierarchical order. Such a choice has been motivated from the fact that the known CKM angles for the quark sector, are relatively small. We consider both possibilities where the Dirac neutrino mass matrix is either the charged lepton or the up-quark mass matrix within the framework of SO(10) GUT with or without supersymmetry. The nonzero texture of the right-handed Majorana neutrino mass matrix M R is used for the generation of the desired bimaximal mixings in a model independent way. Both hierarchical and inverted hierarchical models of the left-handed Majorana neutrino mass matrices are generated and then discussed with examples. The see-saw mass scale which is kept as a free parameter, is predicted in all the examples.

scholarly journals Relaxing cosmological neutrino mass bounds with unstable neutrinos

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Miguel Escudero ◽  
Jacobo Lopez-Pavon ◽  
Nuria Rius ◽  
Stefan Sandner
Keyword(s):  
Neutrino Mass ◽  
Particle Physics ◽  
Goldstone Boson ◽  
Mass Scale ◽  
Simple Extension ◽  
Type I ◽  
Mass Generation ◽  
Age Of The Universe ◽  
Neutrino Mass Models ◽  
The Right

Abstract At present, cosmological observations set the most stringent bound on the neutrino mass scale. Within the standard cosmological model (ΛCDM), the Planck collaboration reports ∑mv< 0.12 eV at 95 % CL. This bound, taken at face value, excludes many neutrino mass models. However, unstable neutrinos, with lifetimes shorter than the age of the universe τν ≲ tU, represent a particle physics avenue to relax this constraint. Motivated by this fact, we present a taxonomy of neutrino decay modes, categorizing them in terms of particle content and final decay products. Taking into account the relevant phenomenological bounds, our analysis shows that 2-body decaying neutrinos into BSM particles are a promising option to relax cosmological neutrino mass bounds. We then build a simple extension of the type I seesaw scenario by adding one sterile state ν4 and a Goldstone boson ϕ, in which νi→ ν4ϕ decays can loosen the neutrino mass bounds up to ∑mv ∼ 1 eV, without spoiling the light neutrino mass generation mechanism. Remarkably, this is possible for a large range of the right-handed neutrino masses, from the electroweak up to the GUT scale. We successfully implement this idea in the context of minimal neutrino mass models based on a U(1)μ−τ flavor symmetry, which are otherwise in tension with the current bound on ∑mv.

Construction of neutrino models with non-vanishing θ13 and leptogenesis

2015 ◽  
Vol 93 (12) ◽  
pp. 1561-1565
Author(s):  
Ng. K. Francis
Keyword(s):  
Neutrino Mass ◽  
Big Bang ◽  
Baryon Asymmetry ◽  
Daya Bay ◽  
Mass Model ◽  
Big Bang Nucleosynthesis ◽  
Great Discovery ◽  
Neutrino Mass Models ◽  
The Universe ◽  
Inflationary Models

We construct the neutrino mass models with non-vanishing θ13 and estimate the baryon asymmetry of the universe and subsequently derive the constraints on the inflaton mass and the reheating temperature after inflation. The great discovery of this decade, the detection of Higgs boson of mass 126 GeV and nonzero θ13, makes leptogenesis all the more exciting. Besides, the neutrino mass model is compatible with inflaton mass 1010–1013 GeV corresponding to reheating temperature TR ∼ 105–107 GeV to overcome the gravitino constraint in supersymmetry and big bang nucleosynthesis. When Daya Bay data θ13 ≈ 9° is included in the model, τ predominates over e and μ contributions, which are indeed a good sign. It is shown that neutrino mass models for a successful leptogenesis can be accommodated for a variety of inflationary models with a rather wide ranging inflationary scale.

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 θ13, μτ SYMMETRY BREAKING AND NEUTRINO YUKAWA TEXTURES

2013 ◽  
Vol 28 (24) ◽  
pp. 1350118 ◽  
Author(s):  
BISWAJIT ADHIKARY ◽  
AMBAR GHOSAL ◽  
PROBIR ROY
Keyword(s):  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Charged Lepton ◽  
Heavy Neutrino ◽  
Type I ◽  
Mixing Angles ◽  
Order Analysis ◽  
A Value ◽  
Mass Matrices ◽  
Best Fit

Within the type-I seesaw and in the basis where charged lepton and heavy neutrino mass matrices are real and diagonal, μτ symmetric four and three zero neutrino Yukawa textures are perturbed by lowest order μτ symmetry breaking terms. These perturbations are taken to be the most general ones for those textures. For quite small values of those symmetry breaking parameters, permitting a lowest order analysis, current best-fit ranges of neutrino mass squared differences and mixing angles are shown to be accommodable, including a value of θ13 in the observed range, provided all the light neutrinos have an inverted mass ordering.

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.

scholarly journals INVERTED NEUTRINO MASS HIERARCHIES FROM U(1) SYMMETRIES

2006 ◽  
Vol 21 (26) ◽  
pp. 5187-5204 ◽  
Author(s):  
G. K. LEONTARIS ◽  
A. PSALLIDAS ◽  
N. D. VLACHOS
Keyword(s):  
Neutrino Mass ◽  
Atmospheric Neutrino ◽  
Vacuum Expectation ◽  
Family Symmetry ◽  
Mixing Angles ◽  
Lepton Flavor ◽  
Left Handed ◽  
Energy Models ◽  
Mass Matrices ◽  
Higgs Fields

Motivated by effective low energy models of string origin, we discuss the neutrino masses and mixing within the context of the Minimal Supersymmetric Standard Model supplemented by a U(1) anomalous family symmetry and additional Higgs singlet fields charged under this extra U(1). In particular, we interpret the solar and atmospheric neutrino data assuming that there are only three left-handed neutrinos which acquire Majorana masses via a lepton number violating dimension-five operator. We derive the general form of the charged lepton and neutrino mass matrices when two different pairs of singlet Higgs fields develop nonzero vacuum expectation values and show how the resulting neutrino textures are related to approximate lepton flavor symmetries. We perform a numerical analysis for one particular case and obtain solutions for masses and mixing angles, consistent with experimental data.

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.

Leptogenesis in quasi-degenerate neutrino mass models with non-zero θ13

2018 ◽  
Vol 96 (1) ◽  
pp. 71-80
Author(s):  
M. Bora ◽  
S. Roy ◽  
N. Nimai Singh
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Baryon Asymmetry ◽  
Neutrino Mass Matrix ◽  
Dirac Neutrino ◽  
Significant Difference ◽  
Down Quark ◽  
Degenerate Neutrino ◽  
Neutrino Mass Models

In the context of neutrino oscillation experiments, six different quasi-degenerate neutrino (QDN) mass models, which we parameterized recently, are found equally relevant. The present attempt tries to explore the possibilities for the discrimination of the six QDN models in the light of baryogenesis via leptogenesis. In this work we investigate all six models to predict observable baryon asymmetry. If leptogenesis is unflavoured or single flavoured, a significant difference is found. Then, only QD-NH-IA and QD-IH-IA are dominant. To get specific results, the choice of Dirac neutrino mass matrix as down-quark type is found most favourable.

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