Related papers: Understanding the differences in neutrino and char…
We explore a possible explanation for the hierarchy in scale between the atmospheric and solar neutrino mass differences ($\lvert \Delta m^{2}_{31} \rvert$, and $\Delta m^{2}_{21}$) through the presence of two distinct neutrino mass…
I attempt to quantify how far from maximal one should expect the atmospheric mixing angle to be given a neutrino mass-matrix that leads, at zeroth order, to a nu_3 mass-eigenstate that is 0% nu_e, 50% nu_mu, and 50% nu_tau. This is done by…
Deviations from expectations have been claimed for solar, atmospheric and high energy prompt neutrinos from charm decay. This information, supplemented only by the existing very good upper limits for oscillations of the $\nu_{\mu}$ at…
I review the construction of a model for lepton masses based on the flavour symmetry group A4 x U(1) reproducing the so-called tri-bimaximal lepton mixing scheme, in eccelent agreement with current data. The model predicts a neutrino…
We study the approximate flavour symmetries imposed on the lepton sector assuming see-saw mechanism as the neutrino mass structure. We apply the symmetry to various neutrino phenomenologies and obtain constraints on neutrino masses and…
The origin of fermion mass hierarchies and mixings is one of the unresolved and most difficult problem in high-energy physics. One possibility to address the flavour problem is by extending the Standard Model to include a family symmetry.…
We consider the neutrino physics of models with a sequentially broken U(2) flavor symmetry. Such theories yield the observed pattern of quark and lepton masses, while maintaining sufficient degeneracies between superparticles of the first…
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…
Approximate flavor symmetries in the quark sector have been used as a handle on physics beyond the Standard Model. Due to the great interest in neutrino masses and mixings and the wealth of existing and proposed neutrino experiments it is…
We analyze the structure of quark and lepton mass matrices under the hypothesis that they are determined from a minimum principle applied to a generic potential invariant under the $\left[SU(3)\right]^5\otimes \mathcal O(3)$ flavor…
A simple ansatz is proposed for neutrino and charged lepton mass matrices, within the framework of universal strength for Yukawa couplings. In this framework all Yukawa couplings have equal moduli and the flavour dependence is only in their…
The fermion mass problem is briefly reviewed. The observed hierarchy of quark and charged lepton masses strongly suggests the existence of an approximately conserved chiral flavour symmetry beyond the Standard Model. It is argued that in…
In the Standard Model, Yukawa couplings parametrize the fermion masses and mixing angles with the exception of neutrino masses. The hierarchies and apparent regularities among the quark and lepton masses are, however, otherwise a mystery.…
We explore predictive flavor models based on subgroups of the standard-model $SU(3)^5$ flavor symmetry. Restricting to products of $SU(3)$, we find that a global $SU(3)^3$ flavor symmetry, broken only by two Yukawa spurions, leads to a…
On account of the new neutrino oscillation data signalling a non-zero value for the smallest mixing angle ($\theta_z$), we present an explicit realization of the underlying U(1) symmetry characterizing the maximal atmospheric mixing angle…
We present a model based on an O(3) flavor symmetry and a minimal extension of the scalar sector to induce hierarchical breaking, O(3) -> O(2) -> SO(2) -> nothing. The model naturally accounts for all the known lepton parameters and yields…
We show that solutions for the masses and mixings of the quarks and leptons based on a $U(1)\times Z_2$ horizontal symmetry are possible. The seesaw mechanism is shown to work consistently in the presence of the discrete symmetry. The…
I report the analysis performed on fermion masses and mixing, including neutrino mixing, within the context of a model with hierarchical radiative mass generation mechanism for light charged fermions, mediated by exotic scalar particles at…
We advance a method used to analyse the neutrino properties (masses and mixing) in the seesaw mechanism. Assuming the hierarchical Dirac and light neutrino masses we establish rather simple relations between the light and the heavy neutrino…
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…