English
Related papers

Related papers: Suppressed $\te_{13}$ In A Democratic Approach

200 papers

We reexamine the democratic neutrino mixing ansatz, in which the mass matrices of charged leptons and Majorana neutrinos arise respectively from the explicit breaking of S(3)_L x S(3)_R and S(3) flavor symmetries. It is shown that a…

High Energy Physics - Phenomenology · Physics 2009-11-10 Harald Fritzsch , Zhi-zhong Xing

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 described by a…

High Energy Physics - Phenomenology · Physics 2009-10-28 Harald Fritzsch

We discuss the possibility of flavor symmetries to explain the pattern of charged lepton and neutrino masses and mixing angles. We emphasize what are the obstacles for the generation of an almost maximal atmospheric mixing and what are the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shao-Long Chen , Michele Frigerio , Ernest Ma

We present a model for lepton masses and mixing angles using the deconstruction setup, based on a non-Abelian flavor symmetry which is a split extension of the Klein group. The symmetries enforce an approximately maximal atmospheric mixing…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gerhart Seidl

We propose a discrete non-abelian symmetry group which enforces maximal atmospheric neutrino mixing, while $\theta_{13} = 0$ and the solar mixing angle $\theta_{12}$ remains undetermined; without finetuning, $\theta_{12}$ will be large but…

High Energy Physics - Phenomenology · Physics 2015-06-25 W. Grimus , L. Lavoura

We show that there is a minimal discrete symmetry which leads to the extended flavour democracy scenario constraining the Dirac neutrino, the charged lepton and the Majorana neutrino mass term ($M_R$) to be all proportional to the…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. C. Branco , J. I. Silva-Marcos

In the context of a minimal extension of the Standard Model with three extra heavy right-handed neutrinos, we propose a model for neutrino masses and mixing based on the hipothesis of a complete alignment of the lepton mass matrices in…

High Energy Physics - Phenomenology · Physics 2009-10-31 F. R. Joaquim

An attempt is made to explore the possibility for deviations of solar mixing angle ($\theta_{12}$) from tri-bimaximal mixings, without sacrificing the predictions of maximal atmospheric mixing angle ($\theta_{23}=\pi/4$) and zero reactor…

High Energy Physics - Phenomenology · Physics 2008-11-26 N. Nimai Singh , Monisa Rajkhowa , Abhijit Borah

We present a model for leptonic mixing and the lepton masses based on flavor symmetries and higher-dimensional mass operators. The model predicts bilarge leptonic mixing (i.e., the mixing angles theta_{12} and theta_{23} are large and the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Tommy Ohlsson , Gerhart Seidl

We consider lepton mixing in an extension of the Standard Model with three right-handed neutrino singlets. We require that the three lepton numbers L_e, L_\mu, and L_\tau be separately conserved in the Yukawa couplings, and we assume that…

High Energy Physics - Phenomenology · Physics 2010-02-03 W. Grimus , L. Lavoura

In the framework of a minimal extension of the SM, where the only additional fields are three right-handed neutrinos, we suggest that the charged lepton, the Dirac neutrino and the right-handed Majorana neutrino mass matrices are all, to…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Kh. Akhmedov , G. C. Branco , F. R. Joaquim , J. I. Silva-Marcos

Encouraged by the latest SNO results, we consider the lepton mixing matrix in the approximation that the nu_2 mass eigenstate is trimaximally (democratically) mixed. This suggests a new parameterization of the remaining mixing degrees of…

High Energy Physics - Phenomenology · Physics 2011-09-29 James D. Bjorken , P. F. Harrison , W. G. Scott

We speculate that the mass spectrum of three neutrinos might have a normal hierarchy as that of three charged leptons or that of three up-type (or down-type) quarks. In this spirit, we propose a novel parametrization of the $3\times 3$…

High Energy Physics - Phenomenology · Physics 2009-11-11 Harald Fritzsch , Zhi-zhong Xing

We generalize the democratic neutrino mixing Ansatz by incorporating the type-II seesaw mechanism with S(3) flavor symmetry. We find that bilarge neutrino mixing can naturally appear if the flavor democracy contribution is strongly…

High Energy Physics - Phenomenology · Physics 2009-11-10 Werner Rodejohann , Zhi-zhong Xing

The neutrino mixing matrix U is in general of the form U=U_e^+ U_nu, where U_e arises from the diagonalization of charged leptons and U_nu is from the neutrino sector. We discuss the possibility that U_nu is nearly diagonal (in the…

High Energy Physics - Phenomenology · Physics 2010-04-05 Guido Altarelli , Ferruccio Feruglio , Isabella Masina

To generate the minimal neutrino Majorana mass matrix that has a free solar mixing angle and Delta m_sol^2 = 0 it suffices to implement an O(2) symmetry, or one of its subgroups SO(2), Z_N (N>2), or D_N (N>2). This O(2) generalizes the…

High Energy Physics - Phenomenology · Physics 2012-02-23 Julian Heeck , Werner Rodejohann

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

On the basis of a seesaw-type mass matrix model for quarks and leptons, $M_f \simeq m_L M_F^{-1} m_R$, where $m_L\propto m_R$ are universal for $f=u,d,\nu$ and $e$ (up-quark-, down-quark-, neutrino- and charged lepton-sectors), and $M_F$ is…

High Energy Physics - Phenomenology · Physics 2008-02-03 Yoshio Koide

The leptonic mixing angle $\theta_{13}$ is known to be small. If it is indeed tiny, the simplest explanation is that charged leptons mix only in the $\mu-\tau$ sector and neutrinos only in the 1-2 sector. We show that this pattern may be…

High Energy Physics - Phenomenology · Physics 2010-04-05 Shao-Long Chen , Michele Frigerio , Ernest Ma

Working with a ${\cal U}(1)$ flavor symmetry, we show how the hierarchical structure in the charged fermion sector and a democratic approach for neutrinos that yields large solar and atmospheric neutrino mixings can be simultaneously…

High Energy Physics - Phenomenology · Physics 2011-05-12 Qaisar Shafi , Zurab Tavartkiladze
‹ Prev 1 2 3 10 Next ›