相关论文: Quark Masses and Flat Directions in String Models

The string breaking model of particle production is extended in order to help explain the transverse momentum distribution in elementary collisions. Inspired by an idea of Bialas', we treat the string using a collective coordinate approach.…

We study quark mass matrices derived from magnetized $T^2/\mathbb{Z}_2$ orbifold models. Yukawa matrices at three modular fixed points, $\tau=i, e^{2\pi i/3}$ and $i\infty$ are invariant under $S$, $ST$ and $T$-transformations. We study…

Starting from a weak basis in which the up (or down) quark matrix is diagonal, we obtain an exact set of equations for the quark mass matrix elements in terms of known observables. We make a numerical analysis of the down (up) quark mass…

I investigate two discrete models of random geometries, namely simplicial quantum gravity and quantum string theory. In four-dimensional simplicial quantum gravity, I show that the addition of matter gauge fields to the model is capable of…

We study the general dependence of mixing angles on heavy fermion masses when mass hierarchies exist among the fermions. For two generations and small Cabibbo angle, this angle is directly shown to scale like $\mu_1/m_s \pm \mu_2/m_c$,…

We discuss recent work trying to extract the renormalised quark masses and Lambda, the QCD scale, from dynamical simulations in lattice gauge theory.

Lattice measurements of spatial distributions of the light quark bilinear densities in static mesons allow to test directly and in detail the wave functions of quark models. These distributions are gauge invariant quantities directly…

We show that a simultaneous explanation for fermionic mass hierarchy among and within the fermionic families, quark-mixing, can be obtained in an extension of the standard model, with real singlet scalar fields, which is UV completed by…

We investigate what could be learned about the absolute scale of neutrino masses from comparisons among the patterns within quark and lepton mass hierarchies. First, we observe that the existing information on neutrino masses fits quite…

Using the resolution of the gauge hierarchy problem recently proposed by Randall and Sundrum, we find a natural explanation for the observed fermion masses and mixings of the three Standard Model (SM) generations. Localizing massless SM…

We investigate theories of flavour based on genus $g=2$ modular invariance and analyze how fermion mass hierarchies can be generated in this context, in the vicinity of invariant points or regions in moduli space where a residual symmetry…

We present some piloting calculations of masses and short-range correlation coefficients for the ground states of light and heavy baryons in the framework of the simple approximation within the nonperturbative QCD approach.

A systematic analysis on the phenomenologically allowed textures in Hermitian quark mass matrices with four texture-zeros is presented. The current data allow a full determination of the mass matrix elements, provided that the actual number…

We examine the light quark masses in a standard--like superstring model in the four dimensional free fermionic formulation. We find that the supersymmetry constraints in the observable and hidden sectors eliminate all large contributions to…

We study the dynamics of non-Abelian vortex strings supported in ${\mathcal N}=2$ supersymmetric QCD with the U$(N)$ gauge group and $N_f=N$ quark flavors deformed by the mass $\mu$ of the adjoint matter. In the limit of large $\mu$ the…

Assuming that a horizontal abelian (gauge) symmetry is at the origin of texture zeros in the fermion mass matrices we show how realistic mass patterns can be generated in the presence of scalar fields whose vacuum expectation value breaks…

A suggestive phenomenological relation is found among the lepton and quark masses which suggests a new insight into the problem of generations and also gives a prediction for the top quark mass in agreement with the range of values which is…

We attempt to describe the interplay of confinement and chiral symmetry breaking in QCD by using the string model. We argue that in the quasi-abelian picture of confinement based on the condensation of magnetic monopoles and the dual…

We discuss the issue of fermion mass hierarchies between lepton and quark families in toy models of dynamical generation of fermion masses through minimal Lorentz Invariance Violation. Realistic hierarchies in chiral theories necessitate an…

I present a new model for the quark mass matrices, which uses four scalar doublets together with a horizontal symmetry S3 x Z3. The model is inspired on a suggestion made a few years ago by Ma, but it is different. The predictions |Vts|…