Related papers: Breaking democracy with non renormalizable mass te…
We consider several neutrino mass models in an extra-dimensional setting on a quantitative level. All the models are set in a five-dimensional scenario, with the standard model (SM) particles living on a brane, while three additional SM…
Supersymmetry broken by anomaly mediation suffers from tachyonic slepton masses. A possible solution to this problem results in "decoupling", i.e., the first two generations of sfermions are much heavier than the third one. We note that in…
We propose a non-universal $\mathrm{U}(1)_{X}$ gauge extension to the Standard Model (SM) and an additional Peccei-Quinn (PQ) global symmetry to study the mass hierarchy and strong CP problem. The scheme allows us to distinguish among…
We propose a random matrix theory for QCD in three dimensions with a Chern-Simons term at level $k$ which spontaneously breaks the flavor symmetry according to U($2N_{\rm f}$) $\to $ U($N_{\rm f}+k$)$\times$U($N_{\rm f}-k$). This random…
Within a democratic approach based on discrete symmetries, we show how the charged lepton mass hierarchies and bilarge neutrino mixings can be realized. For the third mixing angle we find $\te_{13}\sim \sq{\fr{\De m_{\rm sol}^2}{\De m_{\rm…
In models with dynamical electroweak symmetry breaking, this breaking is normally communicated to quarks and leptons by a set of vector bosons with masses generated via sequential breaking of a larger gauge symmetry. In reasonably…
We argue that in dynamical models of fermion masses, which explain the three mass scales of the generations of fermions with three separate heavy scales above the electroweak symmetry breaking scale, the off diagonal CKM matrix elements…
We relate here the vacuum structure of chiral symmetry breaking to a wide class of low energy hadronic properties to examine consistency with experimental results. Phase transition of chiral symmetry breaking is described through explicit…
The three-loop non-mixing contributions to the anomalous dimension of the leading order quark pair production current in non-relativistic QCD are computed. It is demonstrated that the renormalization procedure can only be carried out…
If electroweak dynamical symmetry breaking is due to a chiral condensate of color sextet quarks, dynamics analagous to ``walking technicolor'' will enhance the condensate by orders of magnitude compared to the electroweak chiral scale. This…
The recent evidence for neutrino oscillations stimulate us to discuss again the problem of fermion masses and mixings in gauge theories. In the standard model, several forms for quark mass matrices are equivalent. They become ansatze within…
We consider models with broken $\mu$-$\tau$ permutation symmetry through higher dimensional operators renormalizing the lepton kinetic terms in the action. We study the consequences on the structure of the neutrino mass matrix and find in…
Under the assumption that all the gauge groups in supersymmetric theories unify at the fundamental scale, the numbers and the mass scales of messenger quarks and leptons, as well as the beta-function coefficient of the sector for dynamical…
Motivated by recent measurements which strongly support a nonzero reactor mixing angle $\theta_{13}$, we study a deviation from $S_3$ neutrino discrete symmetry by explicitly breaking the neutrino mass matrix with a general retrocirculant…
We propose a new mechanism for explanation of the fermion hierarchy without introducing any family symmetries. Instead, we postulate that different generations live on different branes embedded in a relatively large extra dimension, where…
Recently a new dynamical symmetry breaking model of electroweak interactions was proposed based on interacting fermions. Two fermions of different SU(2) representations form a symmetry breaking condensate and generate the lepton and quark…
Two different approaches to mass and structure of the nucleon are discussed in recent works, ${\it viz.}$ (case 1) the QCD lagrangian evaluated via lattice calculations and (case ii) spontaneous symmetry breaking mediated by the $\sigma$…
We study left-right symmetric quark mass matrices whose up- and down-sectors have the same structure. This type of realistic mass matrices are derived from orbifold models. We cannot derive some of them by using an extra U(1) symmetry.
We consider a direct approach to quark mixing based on the discrete family symmetry Delta (6N^2) in which the Cabibbo angle is determined by a residual Z_2 times Z_2 subgroup to be $|V_{us}|=0.222521$, for $N$ being a multiple of 7. We…
We review recent work on the interplay between broken family symmetries which give rise to approximate texture zeros in the mass matrices of the quarks and leptons and the presence of certain hierarchy patterns in the spectrum of massive…