Related papers: Adjoint SU(5) GUT model with Modular $S_4$ Symmetr…
Recently we have proposed a renormalizable grand unified theory, based on the SU(5) gauge symmetry, where the neutrino masses are generated through the type I and type III seesaw mechanisms. In this letter we study the supersymmetric…
We demonstrate that an $SU(2)_L\times U(1)_Y$ model with the same particle content as Standard Model(SM) and discrete reflection symmetry between second and third generation of leptons give rise to charged lepton and neutrino mass matrices…
We consider a supersymmetric SO(10) model with a SU(3) symmetry of flavour in which fermion masses emerge via the see-saw mixing with superheavy fermions in 16+16bar representations. In this model the dangerous D=5 operators of proton decay…
A nonuniversal abelian extension $\mathrm{U(1)}_{X}$ free from chiral anomalies is introduced into the Standard Model (SM), in order to evaluate its suitability in addressing the fermion mass hierarchy (FMH) by using seesaw mechanisms…
I briefly outline the most prominent features of a novel $SU(5)$ unification model proposal. The particle content of the model comprises $5_H$, $24_H$, $35_H$, ${\overline{5}_F}_i$, ${10_F}_i$, $15_F$, $\overline{15}_F$, and $24_V$, where…
We discuss renormalization effects on neutrino masses and mixing angles in a supersymmetric string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model, with matter in fundamental and antisymmetric tensor representations and singlet Higgs…
The comparison of the CKM mixing angles with the leptonic mixings implied by the recent atmospheric and solar neutrino data exhibits an interesting complementarity. This pattern can be understood in the context of the SU(5) grand…
We present a renormalizable fermion mass model based on the symmetry $Q_4$ that accommodates all fermion masses and mixing angles in both the quark and lepton sectors. It requires the presence of only four SU(2) doublet scalar fields…
It is well known that the supersymmetric finite threshold effects can induce substantial corrections to the Standard Model fermion masses. This opens an alternative possibility to correct the problematic mass ratios of the lighter…
We consider a SU(5) x U(1)_F GUT-flavor model in which the number of effects that determine the charged fermions Yukawa matrices is much larger than the number of observables, resulting in a hierarchical fermion spectrum with no particular…
We explore a new class of supersymmetric models for lepton masses and mixing angles where the role of flavour symmetry is played by modular invariance. The building blocks are modular forms of level N and matter supermultiplets, both…
An additional generation of quarks and leptons and their SUSY counterparts, which are vector-like under the Standard Model gauge group but are chiral with respect to the new U(1)$_{3-4}$ gauge symmetry, are added to the Minimal…
We extend a previously developed description of the flavour parameters in the charged fermion sector, based on a U(2) flavour symmetry, to include two main features of the neutrino sector seemingly implied by recent data: a large mixing…
We propose a model based on SU(5) x {}^{(d)}T which successfully gives rise to near tri-bimaximal leptonic mixing as well as realistic CKM matrix elements for the quarks. The Georgi-Jarlskog relations for three generations are also…
We propose the Fritzsch-Branco-Silva-Marcos type fermion mass matrix, which is a typical texture in the nearest-neighbor interaction form, in SU(5) GUT. By evolution of the mass matrices with SU(5) GUT relations in the minimal SUSY standard…
We design a supersymmetric SU (5) GUT model using \Delta (54), a finite non-abelian subgroup of SU (3)f . Heavy right handed neutrinos are introduced which transform as three-dimensional repre-sentation of our chosen family group. The model…
We extend a fermion mass matrix Ansatz by Giuduce to include neutrino masses. The previous predictions are maintained. With two additional parameters, a large Majorana neutrino mass and a hierarchy factor, we have seven {\it further} low…
It has been recently claimed that the symmetry group S4 yields to the Tri-bimaximal neutrino mixing in a "natural" way from the group theory point of view. Approving of this feature as an indication, we build a supersymmetric model of…
We discuss the implications of large neutrino mixings for grand unified theories based on the seesaw mechanism. In SU(5) GUTs large mixings can be accomodated by means of $U(1)_F$ flavour symmetries. In these models the heavy Majorana…
We explore the low energy phenomenology of an F-theory based SU(5) model which, in addition to the known quarks and leptons, contains Standard Model singlets, and vector-like color triplets and SU(2) doublets. Depending on their masses and…