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Related papers: Dirac Lepton Angle Matrix v.s. Majorana Lepton Ang…

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We study the exactly degenerate case for three lefthanded Majorana neutrinos building a general parametrization for the leptonic mixing matrix characterized by two angles and one CP violating phase and identify a weak-basis invariant…

High Energy Physics - Phenomenology · Physics 2017-08-23 G. C. Branco , M. N. Rebelo , J. I. Silva-Marcos

I present here a concise summary of the preprint arXiv:0707.3024, written in collaboration with A. Anisimov and P. Di Bari. There we discuss leptogenesis when {\em CP} violation stems exlusively from the Dirac phase in the PMNS mixing…

High Energy Physics - Phenomenology · Physics 2008-11-26 Steve Blanchet

We discuss the minimal seesaw model for the Dirac CP violating phase of the lepton mixing matrix. We introduce two right-handed Majorana neutrinos and obtain several textures of the tri-maximal lepton mixing matrices. Moreover, we discuss…

High Energy Physics - Phenomenology · Physics 2018-05-09 Yusuke Shimizu , Kenta Takagi , Morimitsu Tanimoto

We estimate the effect of leptonic CP violating phases in the minimal seesaw model with two heavy neutrinos $N$ by imposing the approximately $\mu-\tau$ symmetry on the model. For $N$ subject to the $\mu-\tau$ symmetry, we find that…

High Energy Physics - Phenomenology · Physics 2008-07-01 Teppei Baba

Recently, the reactor mixing angle $\theta_{13}$ has been measured precisely by Daya Bay, RENO and T2K experiments with a moderately large value. However, the standard form of neutrino mixing patterns such as bimaximal, tri-bimaximal,…

High Energy Physics - Phenomenology · Physics 2015-09-02 Sruthilaya M. , Soumya C. , K. N. Deepthi , R. Mohanta

We obtain predictions for the Majorana phases $\alpha_{21}/2$ and $\alpha_{31}/2$ of the $3\times 3$ unitary neutrino mixing matrix $U = U_e^{\dagger} \, U_{\nu}$, $U_e$ and $U_{\nu}$ being the $3\times 3$ unitary matrices resulting from…

High Energy Physics - Phenomenology · Physics 2016-11-02 I. Girardi , S. T. Petcov , A. V. Titov

The tree level diagonalization of a neutrino mass matrix with both Majorana and Dirac masses is discussed in a general context. Flavor changing neutral currents in such models are inevitable. Rephasing invariant quantities characterizing CP…

High Energy Physics - Phenomenology · Physics 2014-11-17 Dan-Di Wu

We consider a scenario with three Majorana neutrinos in which a discrete, finite flavour group G_f is combined with a generalized CP transformation. We derive conditions for consistently defining such a setup. We show that in general lepton…

High Energy Physics - Phenomenology · Physics 2013-07-03 Ferruccio Feruglio , Claudia Hagedorn , Robert Ziegler

We further study the previously proposed Ansatz, Tr(M)=0, for a prediagonal light Majorana type neutrino mass matrix. If CP violation is neglected this enables one to use the existing data on squared mass differences to estimate (up to a…

High Energy Physics - Phenomenology · Physics 2009-11-10 Salah Nasri , Joseph Schechter , Sherif Moussa

The basic characteristics used for the description of both Dirac and Majorana massive neutrinos are studied. Currently available experimental data for these characteristics are presented with an evidence of possible anomalies beyond the…

High Energy Physics - Phenomenology · Physics 2013-10-23 N. Yu. Zysina , S. V. Fomichev , V. V. Khruschov

Some of the outstanding questions of particle physics today concern the neutrino sector, in particular whether there are more neutrinos than those already known and whether they are Dirac or Majorana particles.There are different ways to…

High Energy Physics - Phenomenology · Physics 2015-05-27 Gorazd Cvetic , Claudio Dib , C. S. Kim , Jilberto Zamora-Saa

We discuss the energy scale profile of the bi-maximal mixing which is given at the GUT energy scale in the minimal SUSY model, associated with an assumption that Y_nu^dagger Y_nu is diagonal, where Y_nu is the neutrino-Yukawa coupling…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tetsuo Shindou , Eiichi Takasugi

Assuming the Majorana nature of massive neutrinos, we generalize the Friedberg-Lee neutrino mass model to include CP violation in the neutrino mass matrix $M^{}_\nu$. We show that a favorable neutrino mixing pattern (with $\theta^{}_{12}…

High Energy Physics - Phenomenology · Physics 2014-11-18 Zhi-zhong Xing , He Zhang , Shun Zhou

We study the implications of having a similarity between quark and lepton mixing in the Dirac sector of the Standard Model plus the right-handed neutrino. This enable us to describe all masses and mixings in the Dirac sector in terms of…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Falcone

For Majorana or Dirac neutrinos, using Fritzsch-like texture 4 zero mass matrices with parallel texture structures for the charged leptons and the Dirac neutrino mass matrix (M_{\nu D}), detailed predictions for cases pertaining to…

High Energy Physics - Phenomenology · Physics 2008-11-26 Gulsheen Ahuja , Sanjeev Kumar , Monika Randhawa , Manmohan Gupta , S. Dev

We diagonalize Majorana neutrino mass matrix with the help of PMNS matrix and obtain analytical relations between the mass matrix elements and mixing parameters, viz., three mixing angles- $\theta_{12}, \theta_{23}, \theta_{13}$ and Dirac…

High Energy Physics - Phenomenology · Physics 2019-05-21 Chandan Duarah

A special form of the $3 \times 3$ Majorana neutrino mass matrix derivable from $\mu - \tau$ interchange symmetry accompanied by a generalized $CP$ transformation was obtained many years ago. It predicts $\theta_{23} = \pi/4$ as well as…

High Energy Physics - Phenomenology · Physics 2015-05-18 Ernest Ma , Alexander Natale , Oleg Popov

We consider a class of models of neutrino mixing with $S_4$ flavour symmetry and generalised CP symmetry, broken to $Z_2$ and $Z_2 \times {\rm CP}$ residual symmetries in the charged lepton and neutrino sectors, respectively. In this…

High Energy Physics - Phenomenology · Physics 2018-03-30 J. T. Penedo , S. T. Petcov , A. V. Titov

We consider the MSSM with see-saw mechanism of neutrino mass generation and soft SUSY breaking with flavour-universal boundary conditions at the GUT scale, in which the lepton flavour violating (LFV) decays \mu\to e + \gamma, \tau\to \mu +…

High Energy Physics - Phenomenology · Physics 2014-11-18 S. T. Petcov , T. Shindou , Y. Takanishi

It is found that the seesaw mechanism not only explains the smallness of neutrino masses but also accounts for the large mixing angles simultaneously, even if the unification of the neutrino Dirac mass matrix with that of up-type quark…

High Energy Physics - Phenomenology · Physics 2009-11-11 H. Tsujimoto