Related papers: Suppressed $\te_{13}$ In A Democratic Approach
This is a review article about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing…
Based on the "democratic" universal seesaw model, where mass matrices $M_f$ of quarks and leptons f_i (f=u,d,\nu,e; i=1,2,3) are given by a seesaw form M_f\simeq -m_L M_F^{-1} m_R, and m_L and m_R are universal for all the fermion sectors,…
In the three-Higgs doublet model (3HDM) frame, we search for discrete flavour symmetries that give relations among the lepton masses and their mixing angles. We explore discreet non-Abelian groups of order less than 1035, treating neutrinos…
The near maximal value for the atmospheric neutrino mixing angle together with the fact that the solar mixing angle satisfies the relation $\sin^2\theta_\odot\simeq {1/3}$ is the basis for the so called tri-bimaximal mixing (tbm) when…
We investigate the possibility of expressing the charged leptons and neutrino mass matrices as linear combinations of generators of a single finite group. Constraints imposed on the resulting mixing matrix by current data restrict the group…
We discuss a particularly symmetric model of neutrino mixings where, with good accuracy, the atmospheric mixing angle theta_{23} is maximal, theta_{13}=0 and the solar angle satisfies sin^2(theta_{12})=1/3 (Harrison-Perkins-Scott (HPS)…
We present a predictive scheme for fermion masses and mixings based on supersymmetric SO(10) which provides an understanding of the observed hierarchies in the charged fermion sector including CKM mixings. In the neutrino sector bi-large…
In our previous paper, we proposed the democratic-type neutrino mass matrix which gives interesting predictions, $\theta_{23}=-\frac{\pi}4$, $|\tan \theta_{12}|=\sqrt{2-3\sin^2 \theta_{13}}$ and $\delta=\frac {\pi}2$, where $\theta_{ij}$ is…
It is shown that the simplest breaking of the subnuclear democracy leads to a successful description of the mixing between the second and third family. In the lepton channel the $\nu _{\mu } - \nu_{\tau }$ oscillations are expected to be…
The renormalization effect on a specific ansatz of lepton mass matrices, arising naturally from the breaking of flavor democracy for charged leptons and that of mass degeneracy for light neutrinos, is studied from a superhigh energy scale…
We impose $O(3)_L\times O(3)_R$ flavor symmetry in the supersymmetric standard model. Three lepton doublets $\ell_i$ transform as an $O(3)_L$ triplet and three charged leptons $\bar e_i$ as an $O(3)_R$ triplet, while Higgs doublets $H$ and…
The recent measurement of the third lepton mixing angle, \theta_{13}, has shown that, although small compared to \theta_{12} and \theta_{23}, it is much larger than anticipated in schemes that generate Tri-Bi-Maximal (TBM) or Golden Ratio…
Inspired by the recent T2K indication of a relatively large theta_{13}, we provide a systematic study of some general modifications to three mostly discussed neutrino mixing patterns, i.e., tri-bimaximal, bimaximal and democratic mixing…
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal. We argue that this structure suggests a family symmetric origin in which the magnitude of the…
Status of the discrete symmetry approach to explanation of the lepton masses and mixing is summarized in view of recent experimental results, in particular, establishing relatively large 1-3 mixing. The lepton mixing can originate from…
The Daya Bay Collaboration has recently reported the precise measurement of $\theta_{13}\simeq 8.8^\circ \pm 0.8^\circ $ or $\theta_{13} \neq 0$ at 5.2 \sigma level. The observed non-zero $\theta_{13}$ can be accommodated by some general…
Recent neutrino oscillation data hint that the smallest neutrino mixing angle theta_{13} is possible to lie in the range 5^\circ \lesssim \theta_{13} \lesssim 12^\circ. We show that reasonable perturbations to the democratic mixing pattern,…
We phenomenologically build a neutrino mass matrix obeying $\mu-\tau$ symmetry with only two parameters, Cabibbo angle $(\lambda)$ and a flavour twister parameter $(\eta)$. For vanishing $\eta$, the model assumes TBM mixing. When…
Neutrino mixing is studied from a symmetry perspective, both bottom-up and top-down. In the bottom-up approach, we start from the tri-bimaximal mixing, or one of its three partial patterns, and construct a list of horizontal symmetry groups…
We present a warped extra dimension model with the custodial symmetry $SU(2)_L\times SU(2)_R\times U(1)_X\times P_{LR}$ based on the flavor symmetry $S_4\times Z_2\times Z'_2$, and the neutrinos are taken to be Dirac particles. At leading…