Related papers: Doubly Lopsided Mass Matrices from Supersymmetric …
A Supersymmetric Grand unified model is constructed based on SO(10)xSO(10) symmetry in which new types of Yukawa matrices couple standard and exotic fermions. Evolution of these couplings from the Grand Unified scale to the electroweak…
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.…
We review recent developments in models of neutrino masses and mixing. Emphases are given to models based on finite group family symmetries from which the tri-bimaximal neutrino mixing can arise. In particular, we describe one recent model…
Supersymmetric theories involving a spontaneously broken flavor symmetry can solve the flavor-changing problem while having quark and lepton masses derived from both $F$ and $D$ terms. As an example, a theory of leptons is constructed in…
Supersymmetric gauge models with local horizontal symmetries are known to generate large flavor changing neutral current effects induced by supersymmetry breaking D-terms. We show how the presence of a U(1) gauge symmetry solves this…
We propose a model which unifies the Left-Right symmetry with the $SU(3)_L$ gauge group, called flipped trinification, and based on the $SU(3)_C\otimes SU(3)_L\otimes SU(3)_R\otimes U(1)_X$ gauge group. The model inherits the interesting…
We consider a large class of models where the SU(5) gauge symmetry and a Froggatt-Nielsen (FN) Abelian flavor symmetry arise from a U(5)\times U(5) quiver gauge theory. An intriguing feature of these models is a relation between the gauge…
We explore generating the dimension five operator leading to neutrino masses by integrating out heavy SU(2)_L triplet fermions. We exhibit a model that has a neutrino mass matrix consistent with observations. In addition, the model is…
If supersymmetry (SUSY) will be discovered, successful models of flavour not only have to provide an explanation of the flavour structure of the Standard Model fermions, but also of the flavour structure of their scalar superpartners. We…
If neutrino masses are obtained via the canonical seesaw mechanism, based on an underlying 2X2 mass matrix, unitarity violation of the neutrino mixing matrix is unavoidable, but its effect is extremely small. On the other hand, in the…
We present a common explanation of the fermion mass hierarchy and the large lepton mixing angles in the context of a grand unified flavor and gauge theory (GUTF). Our starting point is a SU(3)xU(1) flavor symmetry and a SO(10) GUT, a basic…
We propose a model based on the gauge group $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ with an extra $S_{3}$ flavor symmetry, which accounts for the lepton masses and mixing. The small active neutrino masses are generated via a double…
A new viewpoint for the gauge hierarchy problem is proposed: compactification at a large scale, 1/R, leads to a low energy effective theory with supersymmetry softly broken at a much lower scale, \alpha/R. The hierarchy is induced by an…
We study a possible gauge symmetry breaking pattern in an ${\rm SU}(7)$ grand unified theory, which describes the mass origins of all electrically charged SM fermions of the second and the third generations. Two intermediate gauge…
A non anomalous horizontal $U(1)_H$ gauge symmetry can be responsible for the fermion mass hierarchies of the minimal supersymmetric standard model. Imposing the consistency conditions for the absence of gauge anomalies yields the following…
We present a $SU(5)\times U(1)_F$ supersymmetric model for neutrino masses and mixings that implements the seesaw mechanism by means of the heavy SU(2) singlets and triplets states contained in three adjoints of SU(5). We discuss how…
We consider the problem of neutrino masses and mixing within the general framework of standard (type-I) seesaw models leading to three light neutrinos. Under the assumption of a hierarchical neutrino mass spectrum \lambda^4: \lambda : 1,…
We construct a left-right symmetric (LRS) model in five dimensions which accounts naturally for the lepton flavor parameters. The fifth dimension is described by an orbifold, S_1/Z_2 times Z'_2, with a typical size of order TeV^{-1}. The…
Hierarchical masses of quarks and leptons are addressed by imposing horizontal symmetries. In supersymmetric Standard Models, the same symmetries play a role in suppressing flavor violating processes induced by supersymmetric particles.…
It is shown how to use as horizontal symmetry the dicyclic group $Q_6 \subset SU(2)$ in a supersymmetric unification $SU(5)\otimes SU(5)\otimes SU(2)$ where one $SU(5)$ acts on the first and second families, in a horizontal doublet, and the…