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Related papers: Neutrino Mixing: $A_4$ Variations

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We present a concise review of models for neutrino masses and mixings with particular emphasis on recent developments and current problems. We discuss in detail attempts at reproducing approximate tri-bimaximal mixing starting from discrete…

High Energy Physics - Phenomenology · Physics 2007-11-02 Guido Altarelli

Selected topics in neutrino theory are discussed, including tribimaximal mixing and its A_4 realization, variations of the seesaw mechanism allowing for observable deviations from unitarity of the neutrino mixing matrix, and the radiative…

High Energy Physics - Phenomenology · Physics 2009-08-13 Ernest Ma

Two recent examples of non-Abelian discrete symmetries (S_3 and A_4) in understanding neutrino masses and mixing are discussed.

High Energy Physics - Phenomenology · Physics 2009-03-09 Ernest Ma

I propose a model of radiative charged-lepton and neutrino masses with $A_4$ symmetry. The soft breaking of $A_4$ to $Z_3$ lepton triality is accomplished by dimension-three terms. The breaking of $Z_3$ by dimension-two terms allow…

High Energy Physics - Phenomenology · Physics 2016-03-23 Ernest Ma

In this paper, we consider a neutrino mass model based on $A_4$ symmetry. The spontaneous symmetry breaking in this model is chosen to obtain tribimaximal mixing in the neutrino sector. We introduce $Z_2 \times Z_2$ invariant perturbations…

High Energy Physics - Phenomenology · Physics 2022-09-07 Abhish Dev , P. Ramadevi , S. Uma Sankar

We present a model of neutrino mixing based on the flavour group $\Delta(27)$ in order to account for the observation of a non-zero reactor mixing angle ($\theta_{13}$). The model provides a common flavour structure for the charged-lepton…

High Energy Physics - Phenomenology · Physics 2014-06-10 P. F. Harrison , R. Krishnan , W. G. Scott

We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large $\theta_{13}$, possible non maximal $\theta_{23}$, approaching sensitivity on $\delta_{CP}$) and their…

High Energy Physics - Phenomenology · Physics 2022-03-02 Guido Altarelli

In view of the fact that the data on neutrino mixing are still compatible with a situation where Bimaximal mixing is valid in first approximation and it is then corrected by terms of order of the Cabibbo angle, we present examples where…

High Energy Physics - Phenomenology · Physics 2015-05-27 Luca Merlo

The newly proposed finite symmetry Sigma(81) is applied to the problem of neutrino tribimaximal mixing. The result is more satisfactory than those of previous models based on A_4 in that the use of auxiliary symmetries (or mechanisms) may…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ernest Ma

Motivated by dimensional deconstruction, we propose a model of tribimaximal neutrino mixing based on A_4 x A_4 symmetry. In this model, the two triplet symmetry-breaking fields of conventional A_4 models are taken to transform under…

High Energy Physics - Phenomenology · Physics 2011-02-16 Christopher D. Carone , Richard F. Lebed

We consider a model based on $A_4$ symmetry to explain the phenomenon of neutrino mixing. The spontaneous symmetry breaking of $A_4$ symmetry leads to a co-bimaximal mixing matrix at leading order. We consider the effect of higher order…

High Energy Physics - Phenomenology · Physics 2017-04-05 Sruthilaya M. , R. Mohanta

Experimental data have provided stringent constraints on neutrino mixing parameters. In the standard parameterization the mixing angle $\theta_{23}$ is close to $\pi/4$. There are also evidences show that the CP violating phase is close to…

High Energy Physics - Phenomenology · Physics 2015-11-24 Xiao-Gang He

A new idea for neutrino mass was proposed recently, where its smallness is not due to the seesaw mechanism, i.e. not inversely proportional to some large mass scale. It comes from a one-loop mechanism with dark matter in the loop consisting…

High Energy Physics - Phenomenology · Physics 2013-06-06 Subhaditya Bhattacharya , Ernest Ma , Alexander Natale , Ahmed Rashed

It has been shown that tribimaximal mixing can be obtained by some particular breaking pattern of the $A_4$ symmetry, wherein the extra $A_4$ triplet Higgs scalars pick up certain fixed vacuum expectation value (VEV) alignments. We have…

High Energy Physics - Phenomenology · Physics 2014-11-18 Biswajoy Brahmachari , Sandhya Choubey , Manimala Mitra

It is well known that the tri-bimaximal neutrino mixing pattern V_0 can be derived from a class of flavor models with the non-Abelian A_4 symmetry. We point out that small corrections to V_0, which are inherent in the A_4 models and arise…

High Energy Physics - Phenomenology · Physics 2011-01-27 Takeshi Araki , Jianwei Mei , Zhi-zhong Xing

In this talk, I have reviewed few recent models on neutrino masses and mixing. Particularly, I have emphasised on $A_4$ symmetric models.

High Energy Physics - Phenomenology · Physics 2007-05-23 Ambar Ghosal

The structure of the neutrino mixing matrix is indicative of an underlying family symmetry that interrelates the three generations of fermions in the Standard Model. We systematically scan the parameter space of 76 discrete non-Abelian…

High Energy Physics - Phenomenology · Physics 2011-11-01 Akin Wingerter , Krishna Mohan Parattu

I recount briefly the history of neutrino tribimaximal mixing and the use of the discrete family symmetry A(4) in obtaining it.

High Energy Physics - Phenomenology · Physics 2008-11-26 Ernest Ma

We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large $\theta_{13}$, possible non maximal $\theta_{23}$, approaching sensitivity on $\delta_{CP}$) and their…

High Energy Physics - Phenomenology · Physics 2015-06-11 G. Altarelli

Present data on neutrino masses and mixing favor the highly symmetric tribimaximal neutrino mixing matrix which suggests an underlying flavor symmetry. A systematic study of non-abelian finite groups of order $g \leq 31$ reveals that…

High Energy Physics - Phenomenology · Physics 2007-05-23 Paul D. Carr , Paul H. Frampton