Related papers: The right generations
In the Supersymmetric extension of the Standard Model with minimal particle content the three neutrinos can have non trivial masses and mixings, generated at 1 loop due to renormalizable lepton number violating interactions. We show that…
We study an extension of the supersymmetric standard model with four families and gauged horizontal symmetry $SU(4)_H$, in which R parity automatically follows as a consequence of gauge invariance and of the field content of the model.…
We turn back to the hypothesis that the Pauli principle, acting intrinsically within leptons and quarks, is the origin of their three generations. The adequate formalism is based on the generalized Dirac equations arising (in the…
The problem of quark-lepton families is discussed in the "bottom-up" phenomenological approach to the extensions of the Standard model. It provides the possibility of the {\it Horizontal unification} of the three known families on the basis…
We propose a new family structure for the Standard Model fermions, where the muon is assigned to the third family, taking the placeholder from the tau lepton. This reassignment, which is a mere choice of convention in the Standard Model,…
We consider a gauge symmetry extension of the standard model given by $SU(3)_C\otimes SU(2)_L\otimes U(1)_X\otimes U(1)_N\otimes Z_2$ with minimal particle content, where $X$ and $N$ are family dependent but determining the hypercharge as…
We extend the left-right symmetric model with an additional non-abelian $SU(2)$ gauge symmetry. The particle content is augmented by one generation of vector-like fermions transforming under the fundamental representation of this new gauge…
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.…
Generic extensions of the Standard Model that respect baryon and lepton numbers have accidentally stable particles. Typical examples are the lightest exotic neutral fermion, or "neutralino", and fields with non-trivial lepton and baryon…
Previous studies have shown how the three generations of the Standard Model fermions can arise from a single generation in more than four dimensions, and how off-diagonal neutral couplings arise for gauge-boson Kaluza-Klein recurrences.…
We show that the Standard Model Lagrangian, including small neutrino masses, has an anomaly-free discrete Z_6 symmetry. This symmetry can emerge naturally from I^{3}_{R}+L_i+L_j-2L_k gauge symmetry (L_i is the i-th lepton number) and ensure…
We study the flavor dependent $U(1)_{B_i-L_j}$ models, where an $i$th generation of quarks and $j(\neq i)$th generation of leptons are charged. By solving the anomaly free condition for the matter sector of the SM fermions and three…
We propose a model based on the gauge group $SU(4)\times SU(2)_L\times SU(2)_R$ where the Dirac masses of all the known fermions are generated as one-loop radiative corrections. We are able to generate realistic quark and lepton masses and…
If three right-handed neutrinos are added to the Standard Model, then, for the three known generations, there are six quarks and six leptons. It is then natural to assume that the symmetry considerations that have been applied to the quark…
We study the constraints imposed by neutrino oscillation experiments on the minimal extensions of the Standard Model (SM) with $n_R$ gauge singlet fermions ("right-handed neutrinos"), that can account for neutrino masses. We consider the…
Inspired by the small mass-squared difference measured in the solar neutrino oscillation experiments and by the testability, we suggest that a limit of the partial mass degeneracy, in which masses of the first two generation fermions are…
A generic heterotic string theory is uniquely reduced to the standard model in terms of a geometry that transcends compactification. This device also extends the standard model to embrace three generations of fermions, including 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…
Various new physics models, e.g., theories of compositeness, can accommodate the color singlet excited leptons that interact with the leptons, quarks, leptoquarks, etc. A particular type of excited lepton, which at low energies interacts…
Leptogenesis induced by the oscillations of GeV-scale neutrinos provides a minimal and testable explanation of the baryon asymmetry of the Universe. In this work we extend previous studies invoking only two heavy neutrinos to the case of…