Related papers: The fermion mass problem
Recent experimental data provides evidence for neutrino masses and leads to the possibility of leptonic mixing and CP violation. In this work special attention is dedicated to CP violation in the leptonic sector both at low and at high…
We propose a simple phenomenological model of quarks-leptons mass matrices having fundamentally universal symmetry structure. These mass matrices consist of democratic and semi-democratic mass matrix terms commonly to the neutrino and the…
We give an overview of recent progress in the study of fermion mass and flavor mixing phenomena. Mass matrix ansatze are considered within the SM and SUSY GUTs where some predictive frameworks based on SU(5) and SO(10) are reviewed. We…
By extending the lepton sector of standard model to include one sterile neutrino and two sets of new Higgs doublets and right-handed neutrinos, denoted by $(\eta_1, N_1, N_3)$ and $(\eta_2, N_2, N_4)$, with two $Z_2$ symmetries, the puzzles…
With latest experimental data the solar neutrino problem enters new phase when crucial aspects of the problem can be formulated in an essentially (solar) model independent way. Original neutrino fluxes can be considered as free parameters…
In this work we study examples of hierarchical neutrino mass matrices inspired by family symmetries, compatible with experiments on neutrino oscillations, and for which there is a connection among the low energy CP violation phase…
This is a review article about neutrino mass and mixing and flavour model building strategies based on modular symmetry. After an introduction to neutrino mass and lepton mixing, we then turn to the main subject of this review, namely a…
The idea of quark-lepton universality at high energies has recently been explored in unified theories based upon the quartification gauge group SU(3)^4. These schemes encompass a quark-lepton exchange symmetry that results upon the…
It was recently shown by the authors that the Fritzsch ansatz for the quark mass matrices prescribed at the supersymmetric grand unified scale is compatible with a moderately heavy top quark ($m_t \simeq 120-150~GeV$). Here we extend the…
Based on a new approach to quark and lepton masses, where the mass spectra originate in vacuum expectation values of O(3)-flavor 1+5 (gauge singlet) scalars, a neutrino mass matrix of a new type is speculated. The mass matrix is described…
Grand Unified Theories predict relationships between the GUT-scale quark and lepton masses. Using new data in the context of the MSSM, we update the values and uncertainties of the masses and mixing angles for the three generations at the…
We propose an extended 2HDM with $Q_6\times Z_4\times Z_2$ symmetry that can successfully accommodate the SM fermion mass and mixing hierarchy. The tiny masses of the active neutrinos are generated from a type-I seesaw mechanism mediated by…
In modular-invariant models of flavour, hierarchical fermion mass matrices may arise solely due to the proximity of the modulus $\tau$ to a point of residual symmetry. This mechanism does not require flavon fields, and modular weights are…
Against the conventional picture that the mass matrix forms in the quark sectors will take somewhat different structures from those in the lepton sectors, a possibility that all the mass matrices of quarks and leptons have the same form as…
We advocate a new approach to study models of fermion masses and mixings, namely anarchy proposed in hep-ph/9911341. In this approach, we scan the O(1) coefficients randomly. We argue that this is the correct approach when the fundamental…
The recent discovery by SuperKamiokande of evidence for neutrino masses requires the addition of at least seven new parameters to the Standard Model. We discuss the general theoretical schemes which require their inclusion, and point out…
The fermion masses in the standard model are introduced as arbitrary parameters and there is no understanding of their origin. In this letter it is suggested that small non zero neutrino masses may be a reflection of broken stochastic…
Renormalizable lepton number violating interactions that break R-parity can induce a Majorana mass for neutrinos. Based on this, we show that it is possible to obtain a phenomenologically viable neutrino mass matrix that can accommodate…
In supersymmetric models a tree-level neutrino mass could originate from the (weak-scale) superpotential. We propose and examine a realization of that idea, which arises naturally in the framework of a spontaneously broken U(1) R-symmetry.…
If neutrinos have masses, why are they so tiny? Are these masses of the Dirac type or of the Majorana type? We are already familiar with the mechanism of how to obtain a tiny Majorana neutrino mass by the famous see-saw mechanism. The…