Related papers: Dynamical mass matrices from effective superstring…
We suggest the fermion doubling for all quarks and leptons. It is a generalization of the neutrino doubling of the seesaw mechanism. The new quarks and leptons are $SU(2)$ singlets and carry the electromagnetic charges of their lighter…
We are inspired by the facts that M-theory may reconcile the supersymmetric GUT scale with that of quantum gravity, and that it provides new avenues for low-energy supersymmetry breaking, to re-examine a flipped SU(5) model that has been…
We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model…
In this talk we present a numerical lattice study of an SU(3) gauge model where an SU(2) doublet of non-Abelian strongly interacting fermions is coupled to a complex scalar field doublet via a Yukawa and a Wilson-like term. The model enjoys…
In supergravity with modular invariance and horizontal $U(1)_X$ gauge symmetry there is a relation between modular weights and $U(1)_X$ charges. The soft scalar masses are then strongly correlated with Yukawa matrices. The implications for…
We present a composite model of quarks with `effective supersymmetry'. The model is based on the gauge group $(SU(2)_S \times SU(2)_M) \times (SU(2)_U \times SU(2)_C \times SU(2)_T) \times SU(5)_{SM}$, where $SU(5)_{SM}$ is the standard…
We show how quark and lepton mass hierarchies can be reproduced in the framework of modular symmetry. The mechanism is analogous to the Froggatt-Nielsen (FN) mechanism, but without requiring any Abelian symmetry to be introduced, nor any…
The significant heavy threshold effect is found in the supersymmetric SU(5) model with two adjoint scalars, one of which is interpreted as a massive string mode decoupled from the lower-energy particle spectra. This threshold related with…
We review recent work on realistic models that break supersymmetry dynamically and give rise to composite quarks and leptons, all in a single sector. These models have a completely natural suppression of flavor-changing neutral currents,…
The observed hierarchy of the quark and lepton masses and mixing angles has led to the parametrisation of the mass matrices in powers of the Cabibbo angle and a certain number of zeros. The origin of these ``textures'' may lie in symmetries…
In this paper, the issues of the quark mass hierarchies and the Cabbibo Kobayashi Maskawa mixing are analyzed in a class of intersecting D-brane configurations with Standard Model gauge symmetry. The relevant mass matrices are constructed…
We analyze the structure of a recently proposed effective field theory (EFT) for the generation of quark and lepton mass ratios and mixing angles, based on the spontaneous breaking of an SU(3) family gauge symmetry at a high scale F. We…
We discuss the charged and neutral fermion masses and mixings in a supersymmetric SO(10) model with a minimal Higgs sector consisting of the multiplets $10_H$, $45_H$, and $16_H + \overline{16}_H$. In addition to the renormalizable Yukawa…
An effective theory is proposed, combining the standard gauge group $SU(3)_{C}\otimes SU(2)_{L}\otimes U(1)_{Y}$ with a horizontal discrete symmetry. By assigning appropriate charges under this discrete symmetry to the various fermion…
The strongly coupled lattice gauge models with confined fermion and scalar matter fields, which in a certain phase break dynamically a global chiral symmetry, are reconsidered from the point of view of the existence of heavy fermions. If…
We propose new textures for the fermion Yukawa matrices which are generalizations of the so-called Stech ansatz. We discuss how these textures can be realized in supersymmetric grand unified models with horizontal symmetry SU(3)_H among the…
In the so-called yukawaon model, where effective Yukawa coupling constants Y_f^{eff} (f=e,\nu,u,d) are given by vacuum expectation values of gauge singlet scalars (yukawaons) Y_f with 3\times 3 flavor components, it is tried to give a…
We consider a U(1) gauge theory, minimally coupled to a massless Dirac field, where a higher-derivative term is added to the pure gauge sector, as in the Lee-Wick models. We find that this term can trigger chiral symmetry breaking at low…
In this letter we try to answer those of the open questions of the Standard model which concern the appearance of families, mass protection mechanism and the Yukawa couplings - by using the approach (proposed by one of us), which suggests a…
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…