scholarly journals Obtaining nonvanishing 𝜃13 with constrained neutrino Yukawa matrix and implications for flavor model buildings

2017 ◽  
Vol 32 (16) ◽  
pp. 1750080
Author(s):  
Ya Zhao
Keyword(s):  
Mass Matrix ◽  
Majorana Neutrino ◽  
Effective Coupling ◽  
Coupling Matrix ◽  
Linear Combinations ◽  
Mixing Angle ◽  
Specific Choice ◽  
Matrix Formula ◽  
Reactor Mixing ◽  
Majorana Neutrino Mass

Assuming a diagonal Majorana neutrino mass matrix, we investigate the neutrino Yukawa textures which lead to a nonzero reactor mixing angle [Formula: see text]. The neutrino effective coupling matrix [Formula: see text] is pre-diagonalized by a constant mixing pattern [Formula: see text] with a vanishing [Formula: see text]. The resulting pre-diagonal symmetrical matrix [Formula: see text] is set to be four texture zeros with two types of off-diagonal elements nonzero, which are [Formula: see text] and [Formula: see text], respectively. With the expectation of simple textures, we thoroughly classify the linear combinations, [Formula: see text], [Formula: see text] and [Formula: see text] of Yukawa elements [Formula: see text] in the same row, according to the values, vanishing or not. Each set of the classifications can lead to a Yukawa texture which may have implications for the discrete flavor model buildings. We also present a model based on [Formula: see text] according to one set of the constraints on the three combinations with a specific choice of a coefficient in Yukawa texture.

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.

scholarly journals μ − τ reflection symmetry and its explicit breaking for leptogenesis in a minimal seesaw model

2019 ◽  
Vol 34 (39) ◽  
pp. 1950329 ◽  
Author(s):  
Newton Nath
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Neutrino Mass Matrix ◽  
Type I ◽  
Reflection Symmetry ◽  
Matrix Formula ◽  
Set Up ◽  
Majorana Neutrino Mass ◽  
The Given

The minimal seesaw framework, embroiling the Dirac neutrino mass matrix [Formula: see text] and the Majorana neutrino mass matrix [Formula: see text], is quite successful to explain the current global-fit results of neutrino oscillation data. In this context, we consider the most predictive forms of [Formula: see text] and [Formula: see text] with two simple parameters, respectively. Considering these matrices, we obtain the low-energy neutrino mass matrix under type-I seesaw formalism which obeys [Formula: see text] reflection symmetry and predicts [Formula: see text] and [Formula: see text]. In the given set-up, we also evaluate the Baryon Asymmetry of the Universe (BAU) through successful leptogenesis and find that perturbation of [Formula: see text] leads to the observed BAU and breaks exactness of the symmetry. Moreover, we also perform various correlation studies among different parameters in the framework of broken symmetry.

scholarly journals A discrete anatomy of the neutrino mass matrix

2014 ◽  
Vol 29 (33) ◽  
pp. 1450179
Author(s):  
G. K. Leontaris ◽  
N. D. Vlachos
Keyword(s):  
Finite Group ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Current Data ◽  
Neutrino Mass Matrix ◽  
Linear Combinations ◽  
Mixing Angle ◽  
Mass Matrices ◽  
Mixing Matrix ◽  
Charged Leptons

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.

scholarly journals Type II seesaw origin of nonzero θ13, δCP and leptogenesis

2014 ◽  
Vol 29 (22) ◽  
pp. 1450108 ◽  
Author(s):  
Debasish Borah
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Type I ◽  
Type Ii ◽  
Mixing Angle ◽  
Yukawa Couplings ◽  
Minimal Structure ◽  
Reactor Mixing ◽  
The Universe

We discuss the possible origin of nonzero reactor mixing angle θ13 and Dirac CP phase δ CP in the leptonic sector from a combination of type I and type II seesaw mechanisms. Type I seesaw contribution to neutrino mass matrix is of tri-bimaximal (TBM) type which gives rise to vanishing θ13 leaving the Dirac CP phase undetermined. If the Dirac neutrino mass matrix is assumed to take the diagonal charged lepton (CL) type structure, such a TBM type neutrino mass matrix originating from type I seesaw corresponds to real values of Dirac Yukawa couplings in the terms [Formula: see text]. This makes the process of right-handed heavy neutrino decay into a light neutrino and Higgs (N → νH) CP preserving ruling out the possibility of leptogenesis. Here we consider the type II seesaw term as the common origin of nonzero θ13 and δ CP by taking it as a perturbation to the leading order TBM type neutrino mass matrix. First, we numerically fit the type I seesaw term by taking oscillation as well as cosmology data and then compute the predictions for neutrino parameters after the type II seesaw term is introduced. We consider a minimal structure of the type II seesaw term and check whether the predictions for neutrino parameters lie in the 3σ range. We also compute the predictions for baryon asymmetry of the universe by considering type II seesaw term as the only source of CP violation and compare it with the latest cosmology data.

scholarly journals TEXTURE-ZERO MODEL FOR THE LEPTON MASS MATRICES

2012 ◽  
Vol 27 (28) ◽  
pp. 1250159 ◽  
Author(s):  
P. M. FERREIRA ◽  
L. LAVOURA
Keyword(s):  
Mass Spectrum ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Type I ◽  
Mixing Angle ◽  
Mass Matrices ◽  
Neutrino Mass Spectrum ◽  
Texture Zero ◽  
Vanishing Elements ◽  
Reactor Mixing

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.

Applicability of second-order expansion in s13 to explore δCP in small and medium baseline ν experiments

2016 ◽  
Vol 31 (09) ◽  
pp. 1650037
Author(s):  
Mandip Singh
Keyword(s):  
Series Expansion ◽  
Second Order ◽  
Mixing Angle ◽  
First Order ◽  
Long Baseline ◽  
Order Expansion ◽  
Matrix Formula ◽  
Small Baseline ◽  
Reactor Mixing ◽  
Baseline Experiment

The series expansion of neutrino evolution matrix “[Formula: see text]”, up to first-order in small reactor mixing angle [Formula: see text] is very useful formalism to study experiments quantitatively. The formalism has been used especially to investigate CP-violating phase [Formula: see text]. In order to perform a broad investigation for the possible measurement of [Formula: see text] phase, we will study small baseline experiments: Chooz [Formula: see text], T2K [Formula: see text] and ESS [Formula: see text], medium baseline experiment: NO[Formula: see text]A [Formula: see text] and long baseline experiment: LBNE [Formula: see text].

scholarly journals Implications of CP invariants for the flavored hybrid neutrino mass matrix

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Madan Singh ◽  
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Neutrino Mass Matrix ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Weak Basis ◽  
Low Energies ◽  
Necessary And Sufficient ◽  
Majorana Neutrino Mass

Abstract We re-examine the weak basis invariants at low energies proposed by C. Jarlskog and Branco et al. in their earlier analyses, after confronting them with the assumptions of two zeros and an equality between arbitrary non-zero elements in the Majorana neutrino mass matrix in the flavored basis. This particular conjecture is found to be experimentally feasible, as shown by S. Dev and D. Raj in their recent work. The present analysis attempts to find the necessary and sufficient condition for CP invariance for each experimentally viable ansatz pertaining to the model, along with some important implications.

scholarly journals NEUTRINO MASS MATRIX FROM Δ(27) SYMMETRY

2006 ◽  
Vol 21 (25) ◽  
pp. 1917-1921 ◽  
Author(s):  
ERNEST MA
Keyword(s):  
Neutrino Mass ◽  
Simple Form ◽  
Charged Lepton ◽  
Mass Matrix ◽  
Discrete Subgroup ◽  
Majorana Neutrino ◽  
Neutrino Mass Matrix ◽  
Mass Matrices ◽  
Majorana Neutrino Mass

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