Related papers: Mass problem in the Standard Model
We analyze all the possible continuous horizontal gauge groups G_H in relation with their possibility to explain m_b<<m_t. We assume that the only effective fermionic degrees of freedom correspond to the known fermions but allow the…
Massive neutrino is an evidence of new physics beyond the Standard Model. One of the well motivated new physics scenarios is a model with gauged lepton flavor symmetry. We investigate neutrino properties in the minimal…
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…
We explore generalized global symmetries in theories of physics beyond the Standard Model. Theories of $Z'$ bosons generically contain 'non-invertible' chiral symmetries, whose presence indicates a natural paradigm to break this symmetry by…
We consider a left-right symmetric model with an $SU(2)_L$ and an $SU(2)_R$ scalar doublet but without the scalar bidoublet. The charged fermion masses in this model are generated via a universal seesaw mechanism. We add a set of three…
I review promising approaches to neutrino mass models, focussing on three neutrino patterns of neutrino masses and mixing angles, and the corresponding Majorana mass matrices. I discuss the see-saw mechanism, and show how it may be applied…
We discussed neutrino masses and mixings in SUSY SO(10) model where quarks and leptons have Yukawa couplings to at least two 10 and one $\bar{126}$ Higgs scalars. In this model, the Dirac and the right-handed Majorana mass terms are…
We have studied the most general neutrino mass matrices in models with SU(2) and SU(3) horizontal symmetries. Without going into the details of the models it is possible to write down the effective operators, which predict the structure of…
Given the particle content of the standard model without and with a right-handed neutrino, the requirement that all anomalies cancel singles out a set of possible global symmetries which can be gauged. I review this topic and propose a new…
In practically all extentions of the standard model, the neutrinos naturally acquire a mass. The neutrino mass matrix, however, contains many parameters which can neither be predicted by the prevailing models nor can be fitted to the data.…
We propose a non-universal $U(1)_{X}$ extension to the Standard Model with three families and an additional global anomala Peccei-Quinn (PQ) symmetry. The breaking of the former allows us to give masses to the exotic fermionic sector and…
We investigate the possibility of adding a fourth generation of quarks. We also extend the Standard Model gauge group by adding another SU(N) component. In order to cancel the contributions of the fourth generation of quarks to the gauge…
The old issue of why there are more than one family of quarks and leptons is reinvestigated with an eye towards the use of anomaly as a tool for constraining the number of families. It is found that, by assuming the existence of…
We analyze the lepton sector of a Left-Right Model based on the gauge group SU(2)_L x SU(2)_R x U(1), concentrating mainly on neutrino properties. Using the seesaw mechanism and a horizontal symmetry, we keep the right-handed symmetry…
The R-symmetry formalism is applied for the supersymmetric SU(3)_C X SU(3)_L X U(1)_X (3-3-1) model with right-handed neutrinos. For this kind of models, we study generalization of the MSSM relation among R-parity, spin and matter-parity.…
The possibility of generating neutrino mass through see-saw mechanism involving U(1) chiral Peccei-Quinn and scale symmetries breakdown is discussed. We consider a generic scale invariant model which has three Majorana fermions and a…
We investigate the neutrino masses and mixing patten in a version of the $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with one extra exotic charged lepton per family as introduced by Ozer. It is shown that an extended scalar sector,…
A study of the three-family local gauge group SU(3)_c X SU(3)_L X U(1)_X with right-handed neutrinos is carried out. We use the minimal scalar sector able to break the symmetry in a proper way and produce, at the same time, masses for the…
We reconsider models of fermion masses and mixings based on a gauge anomalous horizontal U(1) symmetry. In the simplest model with a single flavon field and horizontal charges of the same sign for all Standard Model fields, only very few…
We study the mixing among different generations of massive neutrino fields in a $SU(2)_L \times SU(2)_R \times U(1)_Y$ gauge theory which includes Majorana and Dirac mass terms in the Yukawa sector. Parity can be spontaneously broken at a…