scholarly journals Neutrino mass matrices from two zero 3 × 2 Yukawa textures and minimal d = 5 entries

2016 ◽  
Vol 31 (13) ◽  
pp. 1650077 ◽  
Author(s):  
Avtandil Achelashvili ◽  
Zurab Tavartkiladze

Aiming to relate leptonic CP violating phase [Formula: see text] to the cosmological CP asymmetry, we study the extension of MSSM by two quasi-degenerate (strictly degenerate at tree level) right-handed neutrinos and consider all possible two texture zero [Formula: see text] Yukawa matrices plus one [Formula: see text] dimension five [Formula: see text] operator contributing to the light neutrino mass matrix. We classify all experimentally viable mass matrices, leading to several predictions, and analytically derive predictive relations. We also relate the CP violating [Formula: see text] phase to the CP phase of the thermal leptogenesis.

2018 ◽  
Vol 2018 ◽  
pp. 1-24
Author(s):  
Madan Singh

We investigate the novel possibilities of hybrid textures comprising a vanishing minor (or element) and two equal elements (or cofactors) in light neutrino mass matrix Mν. Such type of texture structures leads to sixty phenomenological cases each, out of which only fifty-six are viable with texture containing a vanishing minor and an equality between the elements in Mν, while fifty are found to be viable with texture containing a vanishing element and an equality of cofactors in Mν under the current experimental test at 3σ confidence level. Detailed numerical analysis of all the possible cases has been presented.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
E. H. Aeikens ◽  
P. M. Ferreira ◽  
W. Grimus ◽  
D. Jurčiukonis ◽  
L. Lavoura

Abstract We consider the one-loop radiative corrections to the light-neutrino mass matrix and their consequences for the predicted branching ratios of the five lepton-flavour-violating decays $$ {\mathrm{\ell}}_1^{-}\to {\mathrm{\ell}}_2^{-}{\mathrm{\ell}}_3^{+}{\mathrm{\ell}}_3^{-} $$ ℓ 1 − → ℓ 2 − ℓ 3 + ℓ 3 − in a two-Higgs-doublet model furnished with the type-I seesaw mechanism and soft lepton-flavour violation. We find that the radiative corrections are very significant; they may alter the predicted branching ratios by several orders of magnitude and, in particular, they may help explain why BR (μ− → e−e+e−) is strongly suppressed relative to the branching ratios of the decays of the τ−. We conclude that, in any serious numerical assessment of the predictions of this model, it is absolutely necessary to take into account the one-loop radiative corrections to the light-neutrino mass matrix.


2005 ◽  
Vol 20 (36) ◽  
pp. 2767-2774 ◽  
Author(s):  
ERNEST MA

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.


2011 ◽  
Vol 26 (07) ◽  
pp. 501-514 ◽  
Author(s):  
S. DEV ◽  
SHIVANI GUPTA ◽  
RADHA RAMAN GAUTAM

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.


2014 ◽  
Vol 29 (33) ◽  
pp. 1450179
Author(s):  
G. K. Leontaris ◽  
N. D. Vlachos

We investigate the possibility of expressing the charged leptons and neutrino mass matrices as linear combinations of elements of a single finite group. Constraints imposed on the resulting mixing matrix by current data restrict the group types, but allow a nonzero value for the θ13 mixing angle.


2011 ◽  
Vol 26 (08) ◽  
pp. 567-574 ◽  
Author(s):  
ASAN DAMANIK

We construct a neutrino mass matrix Mν via a seesaw mechanism with perturbed invariant under a cyclic permutation by introducing a parameter δ into the diagonal elements of Mν with the assumption that trace of the perturbed Mν is equal to trace of the unperturbed Mν. We found that the perturbed neutrino mass matrices Mν can predict the mass-squared difference [Formula: see text] with the possible hierarchy of neutrino mass is normal or inverted hierarchy. By using the advantages of the mass-squared differences and mixing parameters data from neutrino oscillation experiments, we then have neutrino masses in inverted hierarchy with masses: |m1| = 0.101023 eV , |m2| = 0.101428 eV and |m3| = 0.084413 eV .


2012 ◽  
Vol 27 (28) ◽  
pp. 1250159 ◽  
Author(s):  
P. M. FERREIRA ◽  
L. LAVOURA

We suggest a simple model, based on the type-I seesaw mechanism, for the lepton mass matrices. The model hinges on an Abelian symmetry which leads to mass matrices with some vanishing matrix elements. The model predicts one massless neutrino and Meμ = 0 (M is the effective light-neutrino Majorana mass matrix). We show that these predictions agree with the present experimental data if the neutrino mass spectrum is inverted, i.e. if m3 = 0, provided the Dirac phase δ is very close to maximal (±π/ 2). In the case of a normal neutrino mass spectrum, i.e. when m1 = 0, the agreement of our model with the data is imperfect — the reactor mixing angle θ13 is too small in our model. Minimal leptogenesis is not an option in our model due to the vanishing elements in the Yukawa-coupling matrices.


2020 ◽  
Vol 35 (07) ◽  
pp. 2050039
Author(s):  
Zhen-Hua Zhao ◽  
Xin Zhang ◽  
Shan-Shan Jiang ◽  
Chong-Xing Yue

In this paper, we study the phenomenological implications of enforcing one texture zero on the inverse matrix of the neutrino mass matrix [Formula: see text] that can lead to the trimaximal mixing. It is found that the condition of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] or [Formula: see text] can hold in the case of normal neutrino mass ordering, while the condition of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] or [Formula: see text] can hold in the case of inverted neutrino mass ordering, where [Formula: see text] (for [Formula: see text], [Formula: see text]) denotes the [Formula: see text] entry of the inverse matrix of [Formula: see text]. The ranges of the absolute neutrino mass scale and three CP phases for these cases to hold are studied in some detail. The implications of these cases for the effective neutrino mass [Formula: see text] which controls the rates of the neutrino-less double beta decay processes are also given.


2016 ◽  
Vol 31 (06) ◽  
pp. 1650008 ◽  
Author(s):  
Rupam Kalita ◽  
Debasish Borah

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.


2006 ◽  
Vol 21 (25) ◽  
pp. 1917-1921 ◽  
Author(s):  
ERNEST MA

The discrete subgroup Δ(27) of SU(3) has some interesting properties which may be useful for understanding charged-lepton and neutrino mass matrices. Assigning leptons to the 3 and [Formula: see text] representations of Δ(27), a simple form of the Majorana neutrino mass matrix is obtained and compared to present data.


Sign in / Sign up

Export Citation Format

Share Document