Cornell potential is known to represent the quark-antiquark confinement interaction. In addition potential, there have been other interactions in literature that demonstrate confining structure system. Guendelman has proposed a nonlinear electrodynamics (NED) model which results electric form of this study, we propose two NED models whose potentials. We also study coupling gravity one these are...

We consider heavy quark interactions in quenched and unquenched lattice QCD. In a region just above the deconfinement point, non-Abelian gluon polarization leads to a strong increase in the binding. Comparing quark-antiquark and quark-quark interaction, the dependence of the binding on the separation distance r is found to be the same for the colorless singlet QQ̄ and the colored anti-triplet QQ...

Abstract A new method to study the retardation effects in mesons is presented. Inspired from the covariant oscillator quark model, it is applied to the rotating string model in which a non zero value is allowed for the relative time between the quark and the antiquark. This approach leads to a retardation term which behaves as a perturbation of the meson mass operator. It is shown that this ter...

We implement our past investigations in the quark-antiquark interaction through a non-perturbative running coupling defined in terms of a gluon mass function, similar to that used in some Schwinger-Dyson approaches. This coupling leads to a quarkantiquark potential, which satisfies not only asymptotic freedom but also describes linear confinement correctly. From this potential, we calculate the...

MOST expositions of string theory focus on its possible use as a framework for unifying the forces of nature. But I will take a different tack in this article. Rather than the unification of the forces, I will here describe what one might call the unification of the ideas. Let us begin with the classic and not fully solved problem of ‘quark confinement’. From a variety of experiments, physicist...

We review how a certain effective chiral Lagrangian approach to ππ scattering, πK scattering and η → ηππ decay provides evidence for the existence of light scalars σ(550) and κ(900) as well as describing the f0(980) and the a0(980). An attempt to fit these into a nonet suggests that their structure is closer to a dual quark–dual antiquark than to a quark–antiquark. A possible mechanism to expla...

A review is presented of past and recent attempts to build multiquark states within current models already describing ordinary mesons and baryons. This includes: coherence in the chromomagnetic interaction, tetraquarks with two heavy quarks, Steiner-tree models of confinement, and hadronic molecules, in particular in the hidden-charm sector. Some emphasis is put on the difficulties encountered ...

Excited states of the nucleon are described as RPA configurations on a mean–field ground state taken from the MIT bag model. A residual interaction of a structure as in the Nambu–Jona–Lasinio model is used. The particle-hole states are coupled to good total angular momentum and isospin. Valence excitations of particle-hole type and quark–antiquark (qq) states from the Dirac–sea are included. Th...