相关论文: On the microscopic structure of $\pi NN$, $\pi N\D…
We present a microscopic description of the strong $\pi NN$, $\pi N\Delta$ and $\pi\Delta\Delta$ vertices. Our starting point is a constituent-quark model supplemented by an additional $3q\pi$ non-valence component. In the spirit of chiral…
We report on ongoing work to determine the pion-cloud contribution to the electromagnetic $N\rightarrow\Delta$ transition form factors. The starting point is an $SU(6)$ spin-flavor symmetric constituent-quark model with instantaneous…
Within conventional constituent-quark models hadrons come out as stable bound states of the valence (anti)quarks. Thereby the resonance character of hadronic excitations is completely ignored. A more realistic description of hadron spectra…
We study the N pi N coupling, in the framework of a QCD-inspired confining Nambu-Jona-Lasinio model. A simple relativistic confining and instantaneous quark model is reviewed. The Salpeter equation for the nucleon and the boosted pion is…
Hadron spectra and other properties of quark systems are studied in the framework of a non-relativistic spin-independent phenomenological model. The chosen confining potential is harmonic, which allowed us to obtain analytical solutions for…
The nonlocal version of the SU(2)xSU(2) symmetric four-quark interaction of the NJL type is considered. Each of the quark lines contains the form factors. These form factors remove the ultraviolet divergences in quark loops. The additional…
We refine the relativistic constituent quark model developed in our previous papers to include the confinement of quarks. It is done, first, by introducing the scale integration in the space of alpha-parameters, and, second, by cutting this…
We examine the contribution of the pion cloud to the electromagnetic $N \rightarrow \Delta$ transition form factors within a relativistic hybrid constituent-quark model. In this model baryons consist not only of the $3q$ valence component,…
The constituent quark model can explain the strong selectivity of the $N\eta$ decay branching ratios of the nucleon resonances if the fine structure interaction between the constituent quarks is described in terms of Goldstone boson…
Functional defects in periodic media confine waves - acoustic, electromagnetic, electronic, spin, etc. - in various dimensions, depending on the structure of the defect. While defects are usually modelled by a superlattice with a typical…
It has become traditional to assume that the Dirac structure of the phenomenological quark confinement potential is scalar $\otimes$ scalar. We use the heavy quark expansion of the Coulomb gauge QCD Hamiltonian and the Flux Tube model to…
The color-flavor locking phenomenon in the magnetic picture can be the microscopic description of the quark confinement in QCD. We demonstrate it in an N=2 supersymmetric SU(Nc)xSU(Nc) quiver gauge theory coupled to Nf flavors of quarks…
Experimental data of the pion charge form factor are well represented by Poincar\'e invariant constituent-quark phenomenology depending on two parameters, a confinement scale and an effective constituent--quark mass. Pion states are…
A composite model of quarks and bosons is proposed in which a spin $1/2$ isospin doublet $\psi$ is the basic building block of quarks and bosons in the standard model. The $\psi$ has two components $v$ and $w$ with charges $Q=\frac{1}{3}e$…
We present a novel relativistic density-functional approach to modeling quark matter with a mechanism to mimic confinement. The quasiparticle treatment of quarks provides their suppression due to large quark selfenergy already at the…
The covariant spectator formalism is used to model the nucleon and the $\Delta$(1232) as a system of three constituent quarks with their own electromagnetic structure. The definition of the ``fixed-axis'' polarization states for the diquark…
We formulate the covariant equations for quark-antiquark bound states in Minkowski space in the framework of the Covariant Spectator Theory. The quark propagators are dressed with the same kernel that describes the interaction between…
In order to get a more realistic description of the hadron spectrum we extend a constituent-quark model by explicit mesonic degrees of freedom. The resulting system of constituent (anti)quarks, which are subject to an instantaneous…
A new suggestion for organizing the charged pseudo scalar mesons is presented. The simple Non-relativistic (NR) potential model employs a single value of the light quark mass and determines the potential coupling constant directly from the…
We construct the full axial current of the constituent quarks by a summation of the infinite number of diagrams describing constituent-quark soft interactions. By requiring that the conservation of this current is violated only by terms of…