Ivo de Medeiros Varzielas

Tribimaximal mixing in a viable family symmetry unified model with an extended seesaw mechanism

We present a grand unified model based on SO(10) with a {delta}(27) family symmetry. Fermion masses and mixings are fitted and agree well with experimental values. An extended seesaw mechanism plays a key role in the generation of the leptonic mixing, which is approximately tribimaximal.

Lepton masses and mixings in an

We propose a renormalizable multi-Higgs model with

A_4

A_{4}\otimes Z_{2}\otimes Z^{\prime}_{2}

multi-Higgs model with a radiative seesaw mechanism

symmetry, accounting for the experimental deviation from the tribimaximal mixing pattern of the neutrino mixing matrix. In this framework we study the charged lepton and neutrino masses and mixings. The light neutrino masses are generated via a radiative seesaw mechanism, which involves a single heavy Majorana neutrino and neutral scalars running in the loops. The obtained neutrino mixings and mass squared splittings are in good agreement with the neutrino oscillation experimental data for both normal and inverted hierarchy. The model predicts an effective Majorana neutrino mass

Invariant approach to CP in family symmetry models

m_{\beta\beta}=

Quasi-degenerate neutrinos and tri-bi-maximal mixing

4 meV and 50 meV for the normal and the inverted neutrino spectrum, respectively. The model also features a suppression of CP violation in neutrino oscillations, a low scale for the heavy Majorana neutrino (few TeV) and, due to the unbroken

A unified model of quarks and leptons with a universal texture zero

Z_2

Bottom-Up Discrete Symmetries for Cabibbo Mixing

symmetry, a natural dark matter candidate.

Fermion Masses and Mixings and Dark Matter Constraints in a Model with Radiative Seesaw Mechanism

We propose the use of basis invariants, valid for any choice of CP transformation, as a powerful approach to studying specific models of CP violation in the presence of discrete family symmetries. We illustrate the virtues of this approach for examples based on

Neutrino Mixing in Unified Extended Seesaw Model

A_4