scholarly journals Leptonic sum rules from flavour models with modular symmetries

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
J. Gehrlein ◽  
M. Spinrath
Keyword(s):  
Neutrino Mass ◽  
Sum Rules ◽  
Mass Scale ◽  
Neutrino Masses ◽  
Mixing Angles ◽  
Mixing Parameters ◽  
Neutrino Experiments ◽  
Parameter Ranges ◽  
Absolute Neutrino Mass ◽  
Analytical Expressions

Abstract Sum rules in the lepton sector provide an extremely valuable tool to classify flavour models in terms of relations between neutrino masses and mixing parameters testable in a plethora of experiments. In this manuscript we identify new leptonic sum rules arising in models with modular symmetries with residual symmetries. These models simultaneously present neutrino mass sum rules, involving masses and Majorana phases, and mixing sum rules, connecting the mixing angles and the Dirac CP-violating phase. The simultaneous appearance of both types of sum rules leads to some non-trivial interplay, for instance, the allowed absolute neutrino mass scale exhibits a dependence on the Dirac CP-violating phase. We derive analytical expressions for these novel sum rules and present their allowed parameter ranges as well as their predictions at upcoming neutrino experiments.

scholarly journals The SO(10)-inspired leptogenesis timely opportunity

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Pasquale Di Bari ◽  
Rome Samanta
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Lower Bounds ◽  
Neutrinoless Double Beta Decay ◽  
Mass Scale ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Parameters ◽  
Absolute Neutrino Mass

Abstract We study the connection between absolute neutrino mass and neutrino mixing parameters within SO(10)-inspired leptogenesis. We show that current favoured values of the unknown neutrino mixing parameters point toward values of the absolute neutrino mass scale that will be fully tested by cosmological observations and neutrinoless double beta decay experiments during next years. In particular, for mD2/mcharm≤ 5, where mD2 is the intermediate Dirac neutrino mass, and for current best fit values of the Dirac phase δ and the atmospheric mixing angle θ23, we derive a lower bound on the neutrinoless double beta decay effective neutrino mass mee ≳ 31 meV and on the sum of the neutrino masses Σimi ≳ 125 meV. These lower bounds hold for normally ordered neutrino masses, as currently favoured by global analyses, and approximately for δ ∈ [155°, 240°] and θ23 in the second octant. If values in this region will be confirmed by future planned long baseline experiments, then a signal at next generation neutrinoless double beta decay experiments is expected, despite neutrino masses being normally ordered. Outside the region, the lower bounds strongly relax but a great fraction of the allowed range of values still allows a measurement of the lightest neutrino mass. Therefore, in the next years low energy neutrino experiments will provide a stringent test of SO(10)-inspired leptogenesis, that might result either in severe constraints or in a strong evidence.

scholarly journals MEASURING NEUTRINO MASSES AND DARK ENERGY

2008 ◽  
Vol 23 (34) ◽  
pp. 2881-2895
Author(s):  
HUITZU TU
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Neutrino Mass ◽  
Energy Equation ◽  
Mass Scale ◽  
Neutrino Masses ◽  
Acoustic Oscillations ◽  
Distance Measurements ◽  
The Galaxy ◽  
Absolute Neutrino Mass

We review some recent efforts in determining the absolute neutrino mass scale in cosmology. We illustrate in particular how distance measurements such as the baryon acoustic oscillations and the galaxy weak lensing can break the degeneracy between the neutrino mass and dark energy equation of state parameters.

scholarly journals Theoretical and Phenomenological Status of Neutrino Physics: A Brief Review

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Surender Verma
Keyword(s):  
Neutrino Mass ◽  
Particle Physics ◽  
Recent Observation ◽  
New Physics ◽  
Neutrino Masses ◽  
Mixing Angles ◽  
Mixing Parameters ◽  
Phenomenological Studies ◽  
The Status ◽  
Free Parameters

We present an overview of recent progress in the theoretical and phenomenological studies of neutrino masses, lepton avor mixing, and CP violation. Firstly, We discuss the status of neutrino mass with in the Standard Model (SM) of particle physics. Then the possible ways in which neutrino mass terms can be included in the SM are discussed. The inclusion of new physics beyond the SM inevitably brings new parameters which are not constrained by the present experimental data on neutrino masses and mixing angles and, thus, are free parameters of the theory. We, also, discuss various theoretically motivated phenomenological approaches which can be used to reduce the number of free parameters and, thus, provide an excellent tool to understand the underlying physics of neutrino masses and mixings. Current experimental constraints on the neutrino mass spectrum and the lepton avor mixing parameters, including the recent observation of nonzeroθ13, have been summarized. Finally, We discuss the renewed interest in the possible existence of one or more sterile neutrinos and their phenomenology.

scholarly journals On Q6 flavor symmetry and the breaking of μ ↔ τ symmetry

2017 ◽  
Vol 32 (28n29) ◽  
pp. 1750171 ◽  
Author(s):  
Juan Carlos Gómez-Izquierdo ◽  
F. Gonzalez-Canales ◽  
M. Mondragón
Keyword(s):  
Neutrino Mass ◽  
Mass Spectra ◽  
Mass Scale ◽  
Double Beta Decay ◽  
Supersymmetric Model ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Inverted Hierarchy ◽  
Mixing Angles ◽  
Good Agreement

In the simplest version of a [Formula: see text] flavored supersymmetric model, we analyze the leptonic masses and mixings in the framework of a soft breaking of the [Formula: see text] symmetry. This breaking is controlled by the inequality [Formula: see text] in the effective neutrino mass. As a consequence of this breaking, the reactor and atmospheric angles are deviate from [Formula: see text] and [Formula: see text], respectively. Such deviations can be enhanced or suppressed by the CP parities in the Majorana phases, so an analytic study is carried out to remark their importance to constrain the free parameters that accommodate the mixing angles. The normal hierarchy is completely discarded in this model, the inverted hierarchy is less favored than the degenerate one where the reactor and atmospheric angles are in good agreement with the experimental data. Additionally, the model predicts defined regions for the effective neutrino mass decay, the neutrino mass scale and the sum of the neutrino masses in the inverted and degenerate mass spectra. Thus, this model may be testable by future experiments that focus on neutrinoless double beta decay.

scholarly journals ANSATZ FOR QUARK, CHARGED LEPTON, AND NEUTRINO MASSES IN SUSY GUTs

1993 ◽  
Vol 08 (22) ◽  
pp. 2099-2109 ◽  
Author(s):  
H. DREINER ◽  
G.K. LEONTARIS ◽  
N.D. TRACAS
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Mass Scale ◽  
Fermion Mass ◽  
Neutrino Masses ◽  
Mixing Angles ◽  
Tau Neutrino ◽  
The Masses ◽  
Majorana Neutrino Mass

We extend a fermion mass matrix ansatz by Giudice to include neutrino masses. The previous predictions are maintained. With two additional parameters, a large Majorana neutrino mass and a hierarchy factor, we have seven further low energy predictions: the masses of the neutrinos, the mixing angles and the phase in the leptonic sector. We choose a reasonable hierarchy of Majorana masses and fit the overall mass scale according to a solution of the solar neutrino problem via the MSW mechanism, which is in agreement with the 37 Cl , Kamiokande, SAGE and GALLEX data. We then also obtain a cosmologically interesting tau-neutrino mass.

scholarly journals Parametrization of the Yukawa matrix in the scotogenic model and single-zero textures of the neutrino mass matrix

2019 ◽  
Vol 34 (19) ◽  
pp. 1950098 ◽  
Author(s):  
Teruyuki Kitabayashi
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Branching Ratio ◽  
Neutrino Mass Matrix ◽  
Neutrino Masses ◽  
Neutrino Sector ◽  
The One ◽  
Relic Abundance ◽  
Analytical Expressions ◽  
Data Group

As the first topic, we propose a new parametrization of the complex Yukawa matrix in the scotogenic model. The new parametrization is compatible with the particle data group parametrization of the neutrino sector. Some analytical expressions for the neutrino masses with the new parametrization are shown. As the second topic, we consider the phenomenology of the scotogenic model with the one-zero-textures of the neutrino flavor mass matrix. One of the six patterns of the neutrino mass matrix is favorable for the real Yukawa matrix. On the other hand, for the complex Yukawa matrix, five of the six patterns are compatible with observations of the neutrino oscillations, dark matter relic abundance and branching ratio of the [Formula: see text] process.

Absolute neutrino mass scale: session summary

2015 ◽  
Vol 265-266 ◽  
pp. 333-338
Author(s):  
Paolo Gorla ◽  
Massimiliano Lattanzi
Keyword(s):  
Neutrino Mass ◽  
Mass Scale ◽  
Absolute Neutrino Mass
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