scholarly journals Generalized ℤ2 × ℤ2 in scaling neutrino Majorana mass matrix and baryogenesis via flavored leptogenesis

2017 ◽  
Vol 2017 (12) ◽  
Author(s):  
Roopam Sinha ◽  
Rome Samanta ◽  
Ambar Ghosal
Keyword(s):  
Mass Matrix ◽  
Majorana Mass

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 SEESAW AND LEPTOGENESIS: A TRIANGULAR ANSATZ

2011 ◽  
Vol 26 (18) ◽  
pp. 1375-1379 ◽  
Author(s):  
D. FALCONE
Keyword(s):  
Charged Lepton ◽  
Mass Matrix ◽  
Triangular Matrix ◽  
Unitary Matrix ◽  
Seesaw Mechanism ◽  
Dirac Mass ◽  
Majorana Mass ◽  
Dirac Matrix

A triangular ansatz for the seesaw mechanism and baryogenesis via leptogenesis is explored. In a basis where both the charged lepton and the Majorana mass matrix are diagonal, the Dirac mass matrix can generally be written as the product of a unitary times a triangular matrix. We assume the unitary matrix to be the identity and then an upper triangular Dirac matrix. Constraints from bilarge lepton mixing and leptogenesis are studied.

scholarly journals Time Evolution of Lepton Number Carried by Majorana Neutrinos

2021 ◽  
Author(s):  
Apriadi Salim Adam ◽  
Nicholas J Benoit ◽  
Yuta Kawamura ◽  
Yamato Matsuo ◽  
Takuya Morozumi ◽  
...  
Keyword(s):  
Time Evolution ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Mass Term ◽  
Big Bang ◽  
Mass Hierarchy ◽  
Majorana Mass ◽  
Cosmic Neutrino Background ◽  
Cosmic Neutrino ◽  
Lepton Family

Abstract We revisit the time evolution of the lepton family number for a SU(2) doublet consisting of a neutrino and a charged lepton. The lepton family number is defined through the weak basis of the SU(2) doublet, where the charged lepton mass matrix is real and diagonal. The lepton family number carried by the neutrino is defined by the left-handed current of the neutrino family. For this work we assume the neutrinos have Majorana mass. This Majorana mass term is switched on at time t = 0 and the lepton family number is evolved. Since the operator in the avor eigenstate is continuously connected to that of the mass eigenstate, the creation and annihilation operators for the two eigenstates are related to each other. We compute the time evolution of all lepton family numbers by choosing a specific initial avor eigenstate for a neutrino. The evolution is studied for relativistic and nonrelativistic neutrinos. The nonrelativistic region is of particular interest for the Cosmic Neutrino Background predicted from big bang models. In that region we find the lepton family numbers are sensitive to Majorana and Dirac phases, the absolute mass, and mass hierarchy of neutrinos.

scholarly journals NEUTRINO PARAMETER SPACE FOR A VANISHING ee ELEMENT IN THE NEUTRINO MASS MATRIX

2007 ◽  
Vol 22 (19) ◽  
pp. 1401-1410 ◽  
Author(s):  
S. DEV ◽  
SANJEEV KUMAR
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Parameter Space ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Mass Matrix ◽  
Majorana Mass ◽  
Texture Zero ◽  
Majorana Neutrinos

The consequences of a texture zero at the ee entry of neutrino mass matrix in the flavor basis, which also implies a vanishing effective Majorana mass for neutrinoless double beta decay, have been studied for Majorana neutrinos. The neutrino parameter space under this condition has been constrained in the light of all available neutrino data including the CHOOZ bound on [Formula: see text].

scholarly journals THE TYPE-II SINGULAR SEE-SAW MECHANISM

2007 ◽  
Vol 22 (12) ◽  
pp. 2211-2222 ◽  
Author(s):  
K. L. MCDONALD ◽  
B. H. J. MCKELLAR
Keyword(s):  
Mass Matrix ◽  
The Body ◽  
Type Ii ◽  
Neutrino Spectrum ◽  
Majorana Mass ◽  
Mass Matrices ◽  
Majorana Neutrinos ◽  
Neutrino Fluxes ◽  
The Right ◽  
Structure Result

The singular see-saw mechanism is a variation of the see-saw mechanism whereby the right-chiral neutrino Majorana mass matrix is singular. Previous works employing the singular see-saw mechanism have assumed a vanishing left-chiral Majorana mass matrix. We study the neutrino spectrum obtained under a singular see-saw mechanism when the left-chiral neutrinos possess a nonzero Majorana mass matrix. We refer to this as the type-II singular see-saw mechanism. The resulting neutrino spectrum is found to be sensitive to the hierarchy of the Dirac and Majorana mass scales used and we explore the phenomenological consequences of the candidate hierarchies. The compatibility of the resulting spectra with the body of neutrino oscillation data is discussed. It is found that neutrino mass matrices with this structure result in 3+1 or 2+2 neutrino spectra, making it unlikely that this mass matrix structure is realized in nature. If the left-chiral Majorana mass matrix is also singular we show that a type-II singular see-saw mechanism can realize a spectrum of one active-sterile pseudo-Dirac neutrino in conjunction with two active Majorana neutrinos effectively decoupled from the sterile sector. This realizes a scheme discussed in the literature in relation to astrophysical neutrino fluxes.

scholarly journals Effective Majorana mass matrix from tau and pseudoscalar meson lepton number violating decays

2018 ◽  
Vol 2018 (2) ◽  
Author(s):  
Asmaa Abada ◽  
Valentina De Romeri ◽  
Michele Lucente ◽  
Ana M. Teixeira ◽  
Takashi Toma
Keyword(s):  
Pseudoscalar Meson ◽  
Mass Matrix ◽  
Lepton Number ◽  
Majorana Mass ◽  
Lepton Number Violating

scholarly journals SO(10)-INSPIRED SEESAW MECHANISM

2001 ◽  
Vol 16 (04) ◽  
pp. 609-623 ◽  
Author(s):  
MARIO ABUD ◽  
FRANCO BUCCELLA
Keyword(s):  
Experimental Data ◽  
Solar Neutrino ◽  
Neutrino Oscillations ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Matrix Elements ◽  
Seesaw Mechanism ◽  
Solar Neutrino Problem ◽  
Majorana Mass ◽  
The Matrix

We determine the νR Majorana mass matrix from the experimental data on neutrino oscillations in the framework of a see-saw SO(10) model, where we impose the condition (MR)33=0 to avoid too large fine-tunings in the see-saw formula. We find a class of solutions with the two lowest neutrino masses almost degenerate and the scale of the matrix elements of MR in the range 1011–1012 GeV in agreement with Pati–Salam intermediate symmetry. We find also solutions with smaller neutrino masses, for which the scale of MR depends on the solution to the "solar neutrino problem" and on the value of the component of νe along the highest mass eigenstate, Ue3.

scholarly journals Neutrinos and the structure of space-time

2014 ◽  
Vol 12 (2) ◽  
pp. 179-188
Author(s):  
Argyris Nicolaidis
Keyword(s):  
Neutrino Oscillations ◽  
Sterile Neutrino ◽  
Mass Matrix ◽  
Atmospheric Neutrino ◽  
Mixing Angles ◽  
Dirac Type ◽  
Majorana Mass ◽  
Left Handed ◽  
Proposed Model ◽  
Type Coupling

The phenomenon of neutrino oscillations is studied usually as a mixing between the flavor neutrinos and the neutrinos having a definite mass. The mixing angles and the mass eigenvalues are treated independently in order to accommodate the experimental data. We suggest that neutrino oscillations are connected to the structure of spacetime. We expand on a recently proposed model, where two ?mirror? branes coexist. One brane hosts left-handed particles (our brane), while the other brane hosts right-handed particles. Majorana-type couplings mixes neutrinos in an individual brane, while Dirac-type couplings mixes neutrinos across the brares. We first focus our attention in a single brane. The mass matrix, determined by the Majorana mass, leads to mass eigenstates and further to mixing angles identical to the mixing angles proposed by the tri-bimaximal mixing. When we include the Dirac-type coupling, connecting the two branes, we obtain a definite prediction for the transition to a sterile neutrino (righthanded neutrino). With mL (mR) the Majorana mass for the left (right) brane, we are able to explain the solar and the atmospheric neutrino data with mL = 2mR and mR = 10-2 eV.

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