Related papers: Dynamical Flavor Hierarchy and Heavy Top
In the so-called ``yukawaon" model, the (effective) Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (yukawaons) with $3\times 3$ components. In the present model, all of the VEV matrices…
As an extension of the Standard Model (SM), the 3HDM (Three-Higgs-Doublet Model) defines additional relationships among the fermions. In the visible leptonic Yukawa sector of the 3HDM, we investigate the existence of flavor symmetries under…
Supersymmetric SU(5) GUT augmented with anomaly free U(1)_F flavor symmetry is presented. Very economical field content and U(1)_F charge assignment are obtained by specific construction. In particular, three families of 10+5* chiral…
A U(2)^3 flavour symmetry acting on the first two generations of quarks partially explains the hierarchies of the yukawa couplings, and provides a natural embedding for Supersymmetry with heavier first two generations, where collider…
Radiatively generated fermion masses without tree level Yukawa couplings are re-analyzed within supersymmetric models. Special emphasis is given to the possible appearance of color and charge breaking vacua. Several scenarios in which the…
One way to suppress flavor changing neutral currents or CP violating processes in supersymmetry is to make at least some of the first two generations' scalars superheavy (above ~20 TeV). We summarize the motivations and challenges,…
Strong gauge and top-Yukawa couplings predicted in the presence of extra dimensions lead to a trickle-down effect of the top-coupling through the renormalization group equations for the quark Yukawa matrices. The matrix elements for the u…
A Dualized Standard Model recently proposed affords a natural explanation for the existence of Higgs fields and of exactly 3 generations of fermions, while giving at the same time the observed fermion mass hierarchy together with a…
The combination of flavor symmetries with grand unification is considered: GUT $ \times$ flavor . To accommodate three generations the flavor group SO(3) is used. All fermions transform as 3-vectors under this group. The Yukawa couplings…
We consider the problem of trying to understand the recently measured neutrino data simultaneously with understanding the heirarchical form of quark and charged lepton Yukawa matrices. We summarise the data that a sucessful model of…
The supersymmetric contributions to the Flavor Changing Neutral Current processes may be suppressed by decoupling the scalars of the first and second generations. It is known, however, that the heavy scalars drive the stop mass squareds…
It is possible that the standard model (SM) is replaced around some transition energy $\E_{tr}$ by a new, possibly Higgsless, ``flavor gauge theory'' such that the Yukawa (running) parameters of SM at $E \sim \E_{tr}$ show up an…
According to an idea that effective Yukawa coupling constants Y_f^{eff} are given vacuum expectation values < Y_f> of fields ("Yukawaons") Y_f as Y_f^{eff}=y_f < Y_f>/\Lambda, a possible superpotential form in the charged lepton sector…
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…
A mechanism to generate realistic fermion mass hierarchies based on supersymmetric gauged $U(1)_F$ symmetry in flat five-dimensional (5D) spacetime is proposed. The fifth dimension is compactified on $S^1/Z_2$ orbifold. The standard model…
We investigate the possibility of satisfying the $SU(5)$ boundary condition $\mathbf{Y}^d=\mathbf{Y}^{e\,T}$ at the GUT scale within the renormalizable $R$-parity conserving Minimal Supersymmetric Standard Model (MSSM). Working in the…
We explore predictive flavor models based on subgroups of the standard-model $SU(3)^5$ flavor symmetry. Restricting to products of $SU(3)$, we find that a global $SU(3)^3$ flavor symmetry, broken only by two Yukawa spurions, leads to a…
It is argued with the help of an illustrative model, that the inter--species hierarchy among the fermion masses and the quark mixing angles can be accommodated naturally in the standard model with (approximate) flavor democracy provided…
We study renormalizable extensions of the standard model that contain vector-like fermions in a (single) complex representation of the standard model gauge group. There are 11 models where the vector-like fermions Yukawa couple to the…
The observed hierarchy of quark and lepton masses and mixings may be obtained by adding an abelian family symmetry to the Minimal Supersymmetric Model and coupling quarks and leptons to an electroweak singlet scalar field. In a large class…