Further study on the textures of neutrino mass matrix for maximal atmospherical mixing angle and Dirac 
CP
 phase

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.

Download Full-text

Type II seesaw origin of nonzero θ13, δCP and leptogenesis

International Journal of Modern Physics A ◽

10.1142/s0217751x14501085 ◽

2014 ◽

Vol 29 (22) ◽

pp. 1450108 ◽

Cited By ~ 13

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.

Download Full-text

On the textures of neutrino mass matrix for maximal atmospheric mixing angle and Dirac CP phase

Journal of High Energy Physics ◽

10.1007/jhep10(2018)106 ◽

2018 ◽

Vol 2018 (10) ◽

Cited By ~ 2

Author(s):

Zhi-Cheng Liu ◽

Chong-Xing Yue ◽

Zhen-hua Zhao

Keyword(s):

Neutrino Mass ◽

Mass Matrix ◽

Neutrino Mass Matrix ◽

Mixing Angle

Download Full-text

What if θ13 is small?

Canadian Journal of Physics ◽

10.1139/p06-016 ◽

2006 ◽

Vol 84 (6-7) ◽

pp. 621-623

Author(s):

C S Lam

Keyword(s):

Mass Spectrum ◽

Neutrino Mass ◽

Charged Lepton ◽

Mass Matrix ◽

Neutrino Mass Matrix ◽

Inverted Hierarchy ◽

Seesaw Mechanism ◽

Mixing Angle ◽

Left Handed ◽

The Right

In the basis where the charged lepton mass matrix is diagonal, the left-handed neutrino mass matrix is invariant under the permutation of the second and third generations if, and only if, the reactor angle θ13 is zero and the atmospheric mixing angle θ23 is maximal. In the presence of the seesaw mechanism, this symmetry leads to an inverted hierarchy, with m3 = 0. This inverted mass spectrum is doubly protected if the right-handed neutrinos also have a 2–3 symmetry.PACS No.: 14.60Pq

Download Full-text

PHENOMENOLOGY OF "BIMAXIMAL + DEMOCRATIC" TYPE NEUTRINO MASS MATRIX

Modern Physics Letters A ◽

10.1142/s021773230601944x ◽

2006 ◽

Vol 21 (13) ◽

pp. 1067-1073 ◽

Cited By ~ 2

Author(s):

AMBAR GHOSAL ◽

DEBASISH MAJUMDAR

Keyword(s):

Neutrino Mass ◽

Mass Matrix ◽

Atmospheric Neutrino ◽

Double Beta Decay ◽

Neutrino Mass Matrix ◽

Experimental Results ◽

Neutrino Mixing ◽

Mixing Angle ◽

Mixing Angles ◽

The Masses

We demonstrate that "Bimaximal + Democratic" type neutrino mass matrix can accommodate the deviation of θ⊙ from its maximal value along with the other present-day neutrino experimental results, namely, atmospheric, CHOOZ, neutrinoless double beta decay (ββ0ν) and result obtained from WMAP experiment. We define a function χp in terms of solar and atmospheric neutrino mass squared differences and solar neutrino mixing angle (obtained from different experiments and our proposed texture). The masses and mixing angles are expressed in terms of three parameters in our proposed texture. The allowed region of the texture parameters is obtained through minimization of the above function. The proposed texture crucially depends on the value of the experimental results of ββ0ν experiment among all other above-mentioned experiments. If, in future, ββ0ν experiments, namely, MOON, EXO, GENIUS shift the lower bound on 〈mee〉 at the higher side by one order, the present texture will be ruled out.

Download Full-text

RENORMALIZATION OF THE NEUTRINO MASS MATRIX

Modern Physics Letters A ◽

10.1142/s0217732302009052 ◽

2002 ◽

Vol 17 (36) ◽

pp. 2355-2360 ◽

Cited By ~ 1

Author(s):

T. K. KUO

Keyword(s):

Neutrino Mass ◽

Mass Matrix ◽

Analytic Solutions ◽

Neutrino Mass Matrix ◽

Mass Hierarchy ◽

Mixing Angle ◽

Resonance Behavior ◽

Infinite Mass ◽

Exact Analytic Solutions ◽

Physical Mixing

The renormalization group equations for the general 2 × 2, complex, neutrino mass matrix are shown to have exact, analytic solutions. Simple formulas are given for the physical mixing angle, mass ratio and intrinsic CP phase. We also establish a (complex) renormalization invariant relating these parameters. It is found that the mixing angle exhibits the resonance behavior. Also, the infrared fixed point corresponds to vanishing mixing angle and infinite mass hierarchy.

Download Full-text

Two Higgs singlets \(A_4\) Flavor Symmetry with Minimal Breaking

Communications in Physics ◽

10.15625/0868-3166/24/2/3946 ◽

2014 ◽

Vol 24 (2) ◽

pp. 113 ◽

Cited By ~ 1

Author(s):

Nguyen Thanh Phong

Keyword(s):

Neutrino Mass ◽

Mass Matrix ◽

Baryon Asymmetry ◽

Neutrino Mass Matrix ◽

Flavor Symmetry ◽

Mixing Angle ◽

Mixing Angles ◽

The Universe

We study the seesaw realization of a \(A_4\)model with two Higgs singlets. In this model, the mixing angle \(\theta_{13}\) and leptogenesis are zero if the components of right handed neutrino mass matrix resulting from the two Higgs singlets are exact degenerate. We then study the minimal breaking of the model by a tiny shift between aforementioned components. This minimal breaking results in deviations of lepton mixing angles from their tri-bimaximal mixing values in which the current experimental value of \(\theta_{13}\) can be achieved. Besides, the baryon asymmetry of the Universe is successfully generated through non-zero leptogenesis by the decay of right handed neutrinos.

Download Full-text

Re-examination of Two Zero Texture of Neutrino Mass Matrix After Neutrino-2012

Communications in Physics ◽

10.15625/0868-3166/23/3/3145 ◽

2013 ◽

Vol 23 (3) ◽

pp. 211

Author(s):

Nguyen Thanh Phong

Keyword(s):

Experimental Data ◽

Mass Spectrum ◽

Neutrino Mass ◽

Mass Matrix ◽

Neutrino Mass Matrix ◽

Normal Hierarchy ◽

Mixing Angle ◽

Mass Matrices ◽

Neutrino Mass Spectrum ◽

Current Experimental Data

We re-study the seven neutrino mass matrices with two independent vanishing entries under the latest results of neutrino oscillation experiments after the neutrino - 2012 conference. It is shown that the pattern B 1 could be excluded since this pattern realizes very small value of mixing angle theta13. The remain six textures satisfy the current experimental data. We also find that all seven textures of neutrino mass matrix possess the normal hierarchy of neutrino mass spectrum.

Download Full-text