Related papers: Lepton flavor at the electroweak scale: A complete…
Supersymmetric theories involving a spontaneously broken flavor symmetry can solve the flavor-changing problem while having quark and lepton masses derived from both $F$ and $D$ terms. As an example, a theory of leptons is constructed in…
We construct a left-right symmetric (LRS) model in five dimensions which accounts naturally for the lepton flavor parameters. The fifth dimension is described by an orbifold, S_1/Z_2 times Z'_2, with a typical size of order TeV^{-1}. The…
One of the most important discoveries in particle physics is the observation of nonzero neutrino masses, which dictates that the Standard Model (SM) is incomplete. Moreover, several pieces of evidence of lepton flavor universality violation…
It has been recently claimed that the symmetry group S4 yields to the Tri-bimaximal neutrino mixing in a "natural" way from the group theory point of view. Approving of this feature as an indication, we build a supersymmetric model of…
We present a supersymmetric see-saw $S_4$ model giving rise to the most general neutrino mass matrix compatible with Tri-Bimaximal mixing. We adopt the $S_4\times Z_5$ flavour symmetry, broken by suitable vacuum expectation values of a…
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…
Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the…
The observed pattern of mixing in the neutrino sector may be explained by the presence of a non-Abelian, discrete flavour symmetry broken into residual subgroups at low energies. Many flavour models require the presence of Standard Model…
There are experimental indications of large flavor mixing between $\nu_{\mu }$ and $\nu_{\tau}$. In the unification models, in which the massless sector includes extra particles beyond the standard model, there possibly appear the mixings…
The discrete flavor symmetry A4 explains very well neutrino data at low energy, but it seems difficult to extend it to grand unified models since in general left-handed and right-handed fields belong to different A4 representations.…
In the framework of gauged flavour symmetries, new fermions in parity symmetric representations of the standard model are generically needed for the compensation of mixed anomalies. The key point is that their masses are also protected by…
Lepton flavor violation in various sectors of the theory can bring important effects on neutrino masses and mixing through wave function renormalization. We examine general conditions for flavor structure of radiative corrections producing…
We present a extension of the 3-3-1 gauge model supplemented by an $A_4$ flavor symmetry and cyclic discrete symmetries, including $Z_2$, $Z_2'$, $Z_3$, $Z_4$, $Z_7$ and $Z_{10}$. The model successfully reproduces the observed SM fermion…
In this talk, I present a new framework to understand the long-standing fermion mass hierarchy puzzle. We extend the Standard Model gauge symmetry by an extra local U(1)_S symmetry, broken spontaneously at the electroweak scale. All the SM…
We have investigated a flavour model [1] which inspired by small squared-mass difference measured in solar neutrino oscillation experiments and observability in neutrinoless double beta decay experiments. In our model, the $1^{\rm st.}$ and…
We consider tri-bimaximal lepton mixing within low-scale seesaw schemes where light neutrino masses arise from TeV scale physics, potentially accessible at the Large Hadron Collider (LHC). Two examples are considered, based on the A4 flavor…
I proposed a unified model of particle physic and cosmology in \cite {1}, which can simultaneously account for these origin of the inflation, dark energy, dark matter, neutrino mass and baryon asymmetry. I here focus on the fermion flavor…
Hints of violation of lepton flavor universality in semileptonic $B$ decays have prompted a renewed interest in leptoquarks at the low TeV scale. Among the different scenarios suggested, some happen to violate also lepton number, yet not…
We show that in a large class of models based on anomalous U(1) symmetry which addresses the fermion mass hierarchy problem, leptonic flavor changing processes are induced that are in the experimentally interesting range. The flavor…
We present a renormalizable fermion mass model based on the symmetry $Q_4$ that accommodates all fermion masses and mixing angles in both the quark and lepton sectors. It requires the presence of only four SU(2) doublet scalar fields…