scholarly journals Is left–right symmetry the key?

2017 ◽  
Vol 32 (04) ◽  
pp. 1730004 ◽  
Author(s):  
Goran Senjanović
Keyword(s):  
Standard Model ◽  
Predictive Model ◽  
Neutrino Mass ◽  
Majorana Neutrino ◽  
The Road ◽  
The Standard Model ◽  
Abdus Salam ◽  
Majorana Neutrino Mass ◽  
Complete Analogy

In collaboration with Jogesh Pati, Abdus Salam challenged the chiral gauge nature of the Standard Model by paving the road towards the left-right symmetric electro-weak theory. I describe here the logical and historical construction of this theory, by emphasising the pioneering and key role it played for neutrino mass. I show that it is a self-contained and predictive model with the Higgs origin of Majorana neutrino mass, in complete analogy with the SM situation regarding charged fermions.

INVERSE SEESAW NEUTRINO MASS FROM LEPTON TRIPLETS IN THE U(1)Σ MODEL

2009 ◽  
Vol 24 (31) ◽  
pp. 2491-2495 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
Majorana Neutrino ◽  
Neutrino Masses ◽  
Particle Interactions ◽  
Seesaw Mechanism ◽  
Type Iii ◽  
The Standard Model

The inverse seesaw mechanism of neutrino mass, i.e. [Formula: see text], where ∊L is small, is discussed in the context of the U(1)Σ model. This is a gauge extension of the Standard Model of particle interactions with lepton triplets (Σ+, Σ0, Σ-) as (Type III) seesaw anchors for obtaining small Majorana neutrino masses.

scholarly journals NEW U(1) GAUGE SYMMETRY OF QUARKS AND LEPTONS

2002 ◽  
Vol 17 (09) ◽  
pp. 535-541 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Gauge Symmetry ◽  
Standard Model ◽  
Neutrino Mass ◽  
Majorana Neutrino ◽  
Particle Interactions ◽  
Remarkable Property ◽  
Seesaw Mechanism ◽  
Minimal Standard ◽  
Majorana Neutrino Mass

Instead of anchoring the seesaw mechanism with the conventional heavy right-handed neutrino singlet, a small Majorana neutrino mass may be obtained just as well with the addition of a heavy triplet of leptons per family to the minimal standard model of particle interactions. The resulting model is shown to have the remarkable property of accommodating a new U(1) symmetry which is anomaly-free and may thus be gauged. There are many possible phenomenological consequences of this proposal which may already be relevant in explaining one or two recent potential experimental discrepancies.

scholarly journals Three Flavor Quasi-Dirac Neutrino Mixing, Oscillations and Neutrinoless Double Beta Decay

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1310
Author(s):  
Amina Khatun ◽  
Adam Smetana ◽  
Fedor Šimkovic
Keyword(s):  
Standard Model ◽  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Unitary Matrix ◽  
Neutrino Mixing ◽  
Dirac Neutrino ◽  
The Standard Model ◽  
Majorana Neutrino Mass

The extension of the Standard model by three right-handed neutrino fields exhibit appealing symmetry between left-handed and right-handed sectors, which is only violated by interactions. It can accommodate three flavor quasi-Dirac neutrino mixing scheme, which allows processes with violation of both lepton flavor and total lepton number symmetries. We propose a 6×6 unitary matrix for parameterizing the mixing among three flavors of quasi-Dirac neutrino. This mixing matrix is constructed by two 3×3 unitary matrices that diagonalizes the Dirac mass term in the Lagrangian. By only assuming the Standard Model V−A weak interaction, it is found that probabilities of neutrino oscillations among active flavor states and effective masses measured by single beta decay, by neutrinoless double-beta decay and by cosmology only depend on single 3×3 unitary matrix relevant to mixing of active neutrino flavors. Further, by considering 1σ and 3σ uncertainties in the measured oscillation probability of electron antineutrino from reactor, derivation of the constraint on the Majorana neutrino mass component is demonstrated. The consequence for effective Majorana neutrino mass governing the neutrinoless double-beta decay is discussed.

scholarly journals NEUTRINO MASS MATRICES IN MODELS WITH HORIZONTAL SYMMETRIES

2001 ◽  
Vol 16 (36) ◽  
pp. 2345-2352 ◽  
Author(s):  
ASIM K. RAY ◽  
UTPAL SARKAR
Keyword(s):  
Neutrino Mass ◽  
Majorana Neutrino ◽  
Mass Scale ◽  
Lepton Number ◽  
Yukawa Couplings ◽  
Lepton Number Violation ◽  
Mass Matrices ◽  
The Standard Model ◽  
Low Mass ◽  
Majorana Neutrino Mass

We have studied the most general neutrino mass matrices in models with SU(2) and SU(3) horizontal symmetries. Without going into the details of the models it is possible to write down the effective operators, which predict the structure of the Majorana neutrino mass matrices. Unlike other extensions of the standard model, the structure is now independent of the effective Yukawa couplings and depends entirely on the Higgs which gives mass to the other fermions. In the case of SU(3) symmetries the lowest dimensional operators are forbidden requiring a low mass scale for lepton number violation.

scholarly journals HIDING THE EXISTENCE OF A FAMILY SYMMETRY IN THE STANDARD MODEL

2005 ◽  
Vol 20 (36) ◽  
pp. 2767-2774 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Neutrino Mass Matrix ◽  
Tree Level ◽  
Family Symmetry ◽  
The Standard Model

If a family symmetry exists for the quarks and leptons, the Higgs sector is expected to be enlarged to be able to support the transformation properties of this symmetry. There are, however, three possible generic ways (at tree level) of hiding this symmetry in the context of the Standard Model with just one Higgs doublet. All three mechanisms have their natural realizations in the unification symmetry E6 and one in SO (10). An interesting example based on SO (10)×A4 for the neutrino mass matrix is discussed.

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.

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