English
Related papers

Related papers: Democratic-type neutrino mass matrix

200 papers

Using the seesaw mechanism, we construct a model for the light-neutrino Majorana mass matrix which yields trimaximal lepton mixing together with maximal CP violation and maximal atmospheric-neutrino mixing. We demonstrate that, in our…

High Energy Physics - Phenomenology · Physics 2010-04-21 W. Grimus , L. Lavoura

We demonstrate that `Bimaximal + Democratic' type neutrino mass matrix can accommodate the deviation of $\theta_\odot$ from its maximal value which referred in the literature as `quark-lepton complementarity' along with the other present…

High Energy Physics - Phenomenology · Physics 2009-11-11 Ambar Ghosal , Debasish Majumdar

The discrete non-Abelian symmetry $A_4$, valid at some high-energy scale, naturally leads to degenerate neutrino masses, without spoiling the hierarchy of charged-lepton masses. Realistic neutrino mass splittings and mixing angles (one of…

High Energy Physics - Phenomenology · Physics 2009-09-17 K. S. Babu , Ernest Ma , J. W. F. Valle

The overall characteristics of the solar and atmospheric neutrino oscillation are approximately consistent with a tribimaximal form of the mixing matrix $U$ of the lepton sector. Exact tribimaximal mixing leads to $\theta_{13}=0$. However,…

High Energy Physics - Phenomenology · Physics 2016-05-03 N. Razzaghi , S. S. Gousheh

A model is considered in which the scale of the heavy singlet neutrinos is a few orders of magnitude below the grand unification scale and where right-handed vector bosons play still a negligible role. In a basis with diagonal up-quark and…

High Energy Physics - Phenomenology · Physics 2011-02-01 Berthold Stech

We discuss a neutrino mass matrix $\mathcal{M}_\nu$ originally found by Babu, Ma, and Valle (BMV) and show that this mass matrix can be characterized by a simple algebraic relation. From this relation it follows that atmospheric neutrino…

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

Quasi-degenerate neutrino mass models (QDN) which can explain the current data on neutrino masses and mixings,are studied. In the first part, we study the effect of CP-phases on QDN mass matrix obeying $\mu-\tau$ symmetry in normal…

High Energy Physics - Phenomenology · Physics 2012-06-18 Ng. K. Francis , N. Nimai Singh

In this article, we derive the tiny neutrino masses and mixings from the democratic and diagonal texture approach, which consistent with the recent experimental oscillation data. The unitary rotation matrices, which diagonalize the neutrino…

High Energy Physics - Phenomenology · Physics 2023-05-16 Itishree Sethi , Biswaranjan Behera , Mitesh Kumar Behera

The PMNS neutrino mixing matrix U_{PMNS} is in general a product of two unitary matrices U_{lep} and U_{\nu} arising from the diagonalization of the charged lepton and neutrino mass matrices, U_{PMNS} = U^{\dagger}_{lep} U_{\nu}. Assuming…

High Energy Physics - Phenomenology · Physics 2014-11-17 P. H. Frampton , S. T. Petcov , W. Rodejohann

A model for neutrino masses and mixing is devised appointing the see-saw mechanism. The proffered model is fabricated with a combination of Type -I and Type-II see-saw contributions of which the latter dominates. The scalars and the leptons…

High Energy Physics - Phenomenology · Physics 2018-10-24 Soumita Pramanick

It is well-known that, in the basis where the charged-lepton mass matrix is diagonal, there are seven cases of two texture zeros in Majorana neutrino mass matrices that are compatible with all experimental data. We show that two of these…

High Energy Physics - Phenomenology · Physics 2011-06-07 W. Grimus , P. O. Ludl

We propose a scheme of lepton mixing in which the unitary matrix that diagonalizes the neutrino mass matrix is bimaximal and the deviation from bimaximal of the lepton mixing matrix is due to the unitary matrix that diagonalizes the…

High Energy Physics - Phenomenology · Physics 2009-11-07 C. Giunti , M. Tanimoto

CP violation in neutrino interactions is described by three phases contained in Pontecorvo-Maki-Nakagawa-Sakata mixing matrix ($U_{PMNS}$). We argue that the phenomenologocally consistent result of the Dirac CP violation can be obtained if…

High Energy Physics - Phenomenology · Physics 2015-01-30 Jun Iizuka , Teruyuki Kitabayashi , Yuki Minagawa , Masaki Yasue

In this paper, we derive in a novel approach the possible textures of neutrino mass matrix that can lead to maximal atmospherical mixing angle ($\theta^{}_{23} = \pi/4$) and Dirac CP phase ($\delta = - \pi/2$) in two phenomenologically…

High Energy Physics - Phenomenology · Physics 2019-05-08 Zhi-Cheng Liu , Chong-Xing Yue , Zhen-hua Zhao

We discuss two extensions of the Standard Model based on the seesaw mechanism and on non-abelian family symmetry groups O(2) and $D_4$, respectively. Both models have a twofold-degenerate neutrino Dirac mass matrix $M_D$, a Majorana mass…

High Energy Physics - Phenomenology · Physics 2016-12-07 W. Grimus , L. Lavoura

We propose a novel neutrino mixing pattern in terms of only two small integers 1 and 2 together with their square roots and the imaginary number $i$. This ansatz is referred to as the "tetra-maximal" mixing because it can be expressed as a…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhi-zhong Xing

Contrary to the quark mixing matrix, the lepton mixing matrix could be symmetric. We study the phenomenological consequences of this possibility. In particular, we find that symmetry would imply that |U_{e3}| is larger than 0.16, i.e.,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kathrin A. Hochmuth , Werner Rodejohann

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,…

High Energy Physics - Phenomenology · Physics 2009-10-31 Yoshio Koide , Ambar Ghosal

In the minimal seesaw model, we derive required constraints on Dirac neutrino masses inducing maximal CP violation in neutrino oscillations. If the maximal atmospheric neutrino mixing is further assumed, Dirac neutrino masses are uniquely…

High Energy Physics - Phenomenology · Physics 2016-11-18 Teruyuki Kitabayashi , Masaki Yasuè

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…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Tanimoto , T. Watari , T. Yanagida