Related papers: Lepton Mass Matrix Models
The masses of quarks and leptons suggest a strong hierarchical structure. We argue that their patterns can be reproduced through the introduction of a new Abelian symmetry. The data suggest that this symmetry is anomalous. We suggest that…
We apply the discrete S_3 flavor symmetry to both lepton and quark sectors of the standard model extended by introducing one Higgs triplet and realizing the type-II seesaw mechanism for finite neutrino masses. The resultant mass matrices of…
Relations between bulk mass parameters for fermions propagating in higher dimensions are studied in analogy with the empirical mass relation for charged leptons. Masses of three generation of four-dimensional charged leptons are achieved…
The Standard Model fermion sector is enlarged by either one light singlet vector-like down-type quark or one light vector-like lepton doublet, which might be accommodated within a five-dimensional representation of SU(5). At low energies…
Small neutrino masses can arise in some grand unified models or superstring theories. We consider a model with an enhanced fermion sector containing Dirac neutral heavy leptons. The dependence on the mass and mixing parameters of these new…
We extend a previously developed description of the flavour parameters in the charged fermion sector, based on a U(2) flavour symmetry, to include two main features of the neutrino sector seemingly implied by recent data: a large mixing…
A non-supersymmetric renormalizable $SO(10)$ model is investigated for its viability in explaining the observed fermion masses and mixing parameters along with the baryon asymmetry produced via thermal leptogenesis. The Yukawa sector of the…
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…
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.,…
We study the interplay between flavor symmetries and leptogenesis in the case when the scale of flavor symmetry breaking is higher than the scale at which lepton number is violated. We show that when the heavy Majorana neutrinos belong to…
The properties of light leptoquarks predicted in the context of a simple grand unified theory and their observability at the LHC are investigated. The SU(5) symmetry of the theory implies that the leptoquark couplings to matter are related…
Flavor symmetry has been widely studied for figuring out the masses and mixing angles of standard-model fermions. In this paper we present a framework for handling flavor symmetry breaking where the symmetry breaking is triggered by…
Recent atmospheric neutrino data at Super-Kamiokande suggest the near-maximal flavor mixing. Models for the lepton mass matrix, which give the near-maximal flavor mixing, are discussed in this report. Mass matrix models are classified…
We argue that neutrino mass and dark matter can arise from an approximate $B-L$ symmetry. This idea can be realized in a minimal setup of the flipped 3-3-1 model, which discriminates lepton families while keeping universal quark families…
Assuming Majorana nature of neutrinos, we re-investigate, in the light of the recent measurement of the reactor mixing angle, the allowed ranges for the absolute values of the elements of the neutrino mass matrix in the basis where the…
An attractive explanation for non-zero neutrino masses and small matter antimatter asymmetry of the present Universe lies in "leptogenesis". At present the {\it size} of the lepton asymmetry is precisely known, while the {\it sign} is not…
We derive the lower bound on the absolute scale of lightest neutrino mass for normal hierarchy and inverted hierarchy pattern of light neutrinos by studying the new physics contributions to charged lepton flavour violations in the framework…
We analyze lepton asymmetry induced in the decay of right--handed neutrinos in a class of minimal left--right symmetric models. In these models, which assume low energy supersymmetry, the Dirac neutrino mass matrix is proportional to the…
In this talk I review the present status of neutrino masses and mixing and some of their implications for particle physics phenomenology. I first discuss the minimum extension of the Standard Model of particle physics required to…
There is a group-theoretical connection between fermion mixing matrices and minimal horizontal symmetry groups. Applying this connection to the tri-bimaximal neutrino mixing matrix, we show that the minimal horizontal symmetry group for…