相关论文: (S)quark Masses and Non-Abelian Horizontal Symmetr…
Recent interest in horizontal symmetry model building has been driven mainly by the large top mass and hence strong hierarchy in quark masses, and the possibility of appropriately constrained soft squark mass matrices, in place of an…
We consider the Friedberg-Lee symmetry for the quark sector and show that the symmetry closely relates to both quark masses and mixing angles. We also extend our scheme to the fourth generation quark model and find the relation…
The discrete non-Abelian symmetry $A_4$, valid at some high-energy scale, naturally leads to degenerate neutrino masses, without spoiling the hierarchy of charged-lepton masses. Realistic neutrino mass splittings and mixing angles (one of…
Using as a flavor symmetry a finite nonabelian dicyclic $Q_{2N}$ group, we show how to derive quark mass matrices with two arrangements of symmetric texture zeros which are phenomenologically viable. Three other such acceptable textures in…
In a recent paper a model of quark and lepton masses was proposed. Without any family symmetries almost all the qualitative and quantitative features of the quark and lepton masses and Kobayashi-Maskawa mixing angles are explained,…
Quark mass ratios are expressed within the linear meson model by universal relations involving only the masses and decay constants of the flavored pseudoscalars as well as their wave function renormalization. Quantitative results are in…
We study the hierarchy of quark masses and mixings in a model based on a 5-dimensional spacetime with constant curvature of Randall-Sundrum type with two branes, where the Electroweak Symmetry Breaking is caused dynamically by the…
A radiative model of quark and lepton masses utilizing the binary tetrahedral ($T^{\prime}$) flavor symmetry, or horizontal symmetry, is proposed which produces the first two generation of quark masses through their interactions with…
The successful A4 family symmetry for leptons is applied to quarks, motivated by the quark-lepton assignments of SU(5). Realistic quark masses and mixing angles are obtained, in good agreement with data. In particular, we find a strong…
By studying symmetric mass textures for the up and down quark sectors, and expanding in a small parameter $\lambda \sim sin\theta_C$, bounds are set on entries commonly assumed to vanish. Consequences of a 2 + 1 family structure which can…
We solve the homogeneous Bethe-Salpeter (HBS) equation for the scalar, pseudoscalar, vector, and axial-vector bound states of quark and anti-quark in large Nf QCD with the improved ladder approximation in the Landau gauge. The quark mass…
We show that models with an abelian family symmetry which accounts for the observed hierarchies of masses and mixings in the quark sector may also accomodate quasi-degeneracies in the neutrino mass spectrum. Such approximate degeneracies…
A very simple extension of the standard model to include an Abelian family symmetry is able to describe the hierarchy of quark and lepton masses and their mixing angles together with the unification of gauge couplings. We consider the…
We study systematically the possibility for realizing realistic values of quark mass ratios $m_c/m_t$ and $m_s/m_b$ and the mixing angle $V_{cb}$ by using only renormalizable Yukawa couplings derived from heterotic orbifold models. We…
Corrections to the exact heavy--quark symmetry results are expected to follow the $1/m_{Q}$ mass effect of the heavy--quark. We show, by an explicit calculation, that there is something other than the mass effect that suppresses the…
We explore a framework for the computation of quark mass ratios and CKM mixing angles based on an SU(3) family gauge symmetry. The four ratios md/mb, ms/mb, mu/mt, and mc/mt can be fit at one-loop in the family gauge interaction. The same…
Using a Monte Carlo method, we have directly extracted from the available measurements, the hierarchies among the different elements of the quark mass matrices. To do that, we have first introduced a model independent parameterization for…
We propose a model for the mass matrices of quarks and leptons based on two Abelian flavor symmetries. One is assumed to be broken at a high energy region near the Planck scale. It is used for the Froggatt-Nielsen mechanism in both quark…
We investigate the heavy quark spin symmetry, i.e. the mass degeneracy of pseudo-scalar and vector quarkonia at heavy quark limit, by using the gauge/gravity correspondence. We allow generic D3-like geometry with a flavor D7-brane, to avoid…
In a series of three lectures, I review the theory and phenomenology of heavy quark masses and mixing angles and the status of their determination. In addition, I give an introduction to heavy quark symmetry, with the main emphasis on the…