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 Super-Kamiokande neutrino oscillations and the supersymmetric model

2020 ◽  
Vol 9 ◽  
pp. 14
Author(s):  
A. Faessler
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Electron Neutrino ◽  
Tree Level ◽  
Supersymmetric Model ◽  
Neutrino Masses ◽  
Muon Neutrinos

The standard model predicts a ratio of 2 for the number of atmospheric muon to electron neutrinos, while super-Kamiokande and others measure a much smaller value (1.30±0.02 for super-Kamiokande). Super-Kamiokande is also able to measure roughly the direction and the energy of the neutrinos. The zenith-angle dependence for the muon neutrinos suggests that the muon neutrinos oscillate into a third neutrino species, either into the r neutrino or a sterile neutrino. This finding is inves- tigated within the supersymmetric model. The neutrinos mix with the neutralinos, this meaning the wino, the bino and the two higgsinos. The 7 x 7 mass matrix is calculated on the tree level. One finds that the mass matrix has three linearly dependent rows, which means that two masses are zero. They are identified with the two lightest neutrino masses. The fit of the super-Kamiokande data to oscillations between three neutrinos yields, together with the result of supersymmetry, that the third neutrino mass lies between 2x10^-2 and 10^-1 eV. The two lightest neutrino masses are in supersymmetry on the tree level zero. The averaged electron neutrino mass which is the essential parameter in the neutrinoless double-beta decay is given by {m_ve) ~ m_v3 P_ze < 0.8 x10^-2 eV (95% confidence limit). It is derived from the super-Kamiokande data in this supersymmetric model to be two orders smaller than the best value (1 eV) from the neutrinoless double-beta decay.

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 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 CP violations in a predictive A4 symmetry model

2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
T Phong Nguyen ◽  
L T Hue ◽  
D T Si ◽  
T T Thuc
Keyword(s):  
Neutrino Mass ◽  
Branching Ratio ◽  
Mass Scale ◽  
Double Beta Decay ◽  
Inverted Hierarchy ◽  
Yukawa Couplings ◽  
Cp Violations ◽  
Physical Consequences ◽  
The Right ◽  
O 10

Abstract We will investigate numerically a seesaw model with $A_4$ flavor symmetry to find allowed regions satisfying the current experimental neutrino oscillation data, then use them to predict physical consequences. Namely, the lightest active neutrino mass is of the order of $\mathcal{O}(10^{-2})$ eV. The effective neutrino mass $|\langle m\rangle|$ associated with neutrinoless double beta decay is in the range $[0.002 \,\mathrm{eV},0.038\,\mathrm{eV}]$ and $[0.048\,\mathrm{eV},0.058\,\mathrm{eV}]$, corresponding to the normal and the inverted hierarchy schemes, respectively. Other relations among relevant physical quantities are shown, so that they can be determined if some of them are confirmed experimentally. The recent data of the baryon asymmetry of the Universe ($\eta_B$) can be explained via leptogenesis caused by the effect of the renormalization group evolution on the Dirac Yukawa couplings, provided the right-handed neutrino mass scale $M_0$ ranges from $\mathcal{O}(10^8)$ GeV to $\mathcal{O}(10^{12})$ GeV for $\tan\beta =3$. This allowed $M_0$ range is different from the scale of $\mathcal{O}(10^{13})$ GeV for other effects that also generate a consistent $\eta_B$ from leptogenesis. The branching ratio of the decay $ \mu \rightarrow\,e\gamma$ may reach future experimental sensitivity for very light values of $M_0$. Hence, it will be inconsistent with the $M_0$ range predicted from the $\eta_B$ data whenever this decay is detected experimentally.

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.

Type-I seesaw mechanism for neutrino mass and mixing in gauged B − L model with D4 × Z4 flavor symmetry

2021 ◽  
pp. 2150184
Author(s):  
V. V. Vien ◽  
H. N. Long ◽  
D. P. Khoi
Keyword(s):  
Neutrino Mass ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Type I ◽  
Normal Ordering ◽  
Seesaw Mechanism ◽  
Mixing Angles ◽  
Neutrino Mass And Mixing ◽  
The Standard Model ◽  
Best Fit

In this paper, we study a non-renormalizable [Formula: see text] extension of the Standard Model with [Formula: see text] and [Formula: see text] symmetries accommodating the most recent neutrino data within the type-I seesaw mechanism. The two squared mass differences and three mixing angles can get the best-fit values while the leptonic Dirac CP phase is in [Formula: see text] range of the best-fit values for both normal and inverted orderings. The sum of active neutrino mass and the effective neutrino masses are, respectively, predicted to be [Formula: see text], [Formula: see text] and [Formula: see text] for normal ordering while [Formula: see text], [Formula: see text] and [Formula: see text] for inverted ordering, which are well consistent with the current experimental constraints.

scholarly journals CONSTRAINTS OF MIXING ANGLES FROM NEUTRINO OSCILLATION EXPERIMENTS AND NEUTRINOLESS DOUBLE BETA DECAY

1998 ◽  
Vol 13 (28) ◽  
pp. 2279-2287 ◽  
Author(s):  
TAKESHI FUKUYAMA ◽  
KOUICHI MATSUDA ◽  
HIROYUKI NISHIURA
Keyword(s):  
Beta Decay ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Mixing Angles

From the analyses of the recent data of neutrino oscillation experiments (especially the CHOOZ and the super-Kamiokande experiments), we discuss how these data affect the neutrinoless double beta decay ((ββ)0ν) rate and vice versa assuming that neutrinos are Majorana particles. For the case of m1~m2≪m3 (mi are neutrino masses), we obtain, from the data of the CHOOZ and super-Kamiokande, 0.28 ≲ sin 2θ23≲ 0.76 and sin 2θ13≲ 0.05. Combining the latter constraint with the analysis of the "averaged" neutrino mass <mν> appeared in (ββ)0ν, we find that [Formula: see text], which leads to the constraint on <mν> as <mν> ≲ 0.05m3 + (1 - 0.05)m2. For the case of m1≪m2~ m3, we find that the data of neutrino oscillation experiments and (ββ)0ν imply the following constraints of mixing angles: if 0.95m3≲ <mν> < m3, [Formula: see text]. If <mν> ≲ 0.95m3, [Formula: see text] and [Formula: see text].

scholarly journals Fermion mass and mixing in a low-scale seesaw model based on the S4 flavor symmetry

2019 ◽  
Vol 2019 (11) ◽  
Author(s):  
V V Vien ◽  
H N Long ◽  
A E Cárcamo Hernández
Keyword(s):  
Low Energy ◽  
Spontaneous Breaking ◽  
Fermion Mass ◽  
Recent Experimental Data ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Seesaw Model ◽  
Mixing Parameters ◽  
The Masses ◽  
Good Agreement

Abstract We construct a low-scale seesaw model to generate the masses of active neutrinos based on $S_4$ flavor symmetry supplemented by the $Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group, capable of reproducing the low-energy Standard Model (SM) fermion flavor data. The masses of the SM fermions and the fermionic mixing parameters are generated from a Froggatt–Nielsen mechanism after spontaneous breaking of the $S_4\times Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group. The obtained values for the physical observables of the quark and lepton sectors are in good agreement with the most recent experimental data. The leptonic Dirac CP-violating phase $\delta _\mathrm{CP}$ is predicted to be $259.579^\circ$ and the predictions for the absolute neutrino masses in the model can also saturate the recent constraints.

Fermion masses and mixings in a 3-3-1 model withQ4symmetry

2019 ◽  
Vol 34 (25) ◽  
pp. 1950198
Author(s):  
V. V. Vien ◽  
D. P. Khoi
Keyword(s):  
Neutrino Mass ◽  
Mass Parameter ◽  
Majorana Neutrino ◽  
Tree Level ◽  
Type I ◽  
Inverted Hierarchy ◽  
Quark Masses ◽  
Fermion Masses ◽  
Majorana Neutrino Mass ◽  
Good Agreement

We construct a renormalizable [Formula: see text] model with [Formula: see text] symmetry accommodating the observed pattern of fermion masses and mixings with Dirac CP violation phase. The smallness of the active neutrino masses arises from a combination of type I and type II seesaw mechanisms. Both normal and inverted neutrino mass ordering are viable in our model in which the obtained physical observables of the lepton sector are well consistent with the global fit of neutrino oscillation data [P. F. de Salas et al., Phys. Lett. B 782, 633 (2018)] while the CKM matrix is unity at tree level and the quark masses are in good agreement with the experimental data [Particle Data Group (M. Tanabashi et al.), Phys. Rev. D 98, 030001 (2018)]. Furthermore, the model also predicts an effective Majorana neutrino mass parameter of [Formula: see text] eV for normal hierarchy and [Formula: see text] for inverted hierarchy which are consistent with the constraints given in [P. F. de Salas et al., Phys. Lett. B 782, 633 (2018)].

scholarly journals NEUTRINOLESS DOUBLE BETA DECAY: AN EXTREME CHALLENGE

2013 ◽  
Vol 53 (A) ◽  
pp. 790-792
Author(s):  
Fernando Ferroni
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Neutrinoless Double Beta Decay ◽  
Mass Region ◽  
Double Beta Decay ◽  
Great Power ◽  
Inverted Hierarchy

Neutrino-less Double Beta Decay is the only known way to possibly resolve the nature of neutrino mass. The chances to cover the mass region predicted by the inverted hierarchy require a step forward in detector capability. A possibility is to make use of scintillating bolometers. These devices shall have a great power in distinguishing signals from alfa particles from those induced by electrons. This feature might lead to an almost background-free experiment. Here the Lucifer concept will be introduced and the prospects related to this project will be discussed.

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