Related papers: The $\pi-$Gluon Exchange Interaction Between Const…
The two-pion exchange interaction between constituent quarks is shown to enhance the effect of the the isospin dependent spin-spin component of the one-pion exchange interaction, and to cancel out its tensor component. It therefore provides…
Based on both the constituent quark picture and the instanton model for QCD vacuum, we calculate the unpolarized and polarized gluon distributions in the constituent quark and in the nucleon. Our approach consists of the two main steps. At…
We study the performance of some recent potential models suggested as effective interactions between constituent quarks. In particular, we address constituent quark models for baryons with hybrid Q-Q interactions stemming from one-gluon…
In this work, the different exchange freedom, one gluon, one pion or Goldstone boson, in constituent quark model is investigated, which is responsible to the hyperfine interaction between constituent quarks, via the combined analysis of the…
We investigate the effects of pion and gluon exchanges on the formation of two-flavor color superconductivity at moderate density, $\mu <1 GeV$. The chiral quark model proposed by Manohar and Georgi containing pions as well as gluons is…
The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…
A direct connection can be made between mixing angles in negative parity baryons and the spin coupling of constituent quarks. The mixing angles do not depend on spectral data. These angles are recalculated for gluon exchange and pion…
Different mechanisms have been proposed to account for the spin-dependent interaction between quarks in ground-state hadrons. The first mechanism is the chromomagnetic interaction arising from one-gluon exchange, a second mechanism is an…
We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between quarks. The six-quark harmonic…
By considering a one loop background field method for a nonperturbative one gluon exchange between quarks, leading electromagnetic form factors of pion couplings to constituent quarks are derived by means of from a large quark and gluon…
We study baryon spectroscopy including the effects of pseudoscalar meson exchange and one gluon exchange potentials between quarks, governed by $\alpha_s$. The non-perturbative, hyperspherical method calculations show that one can obtain a…
We consider the pion structure in the region of low and moderately high momentum transfers: at low $Q^2$, the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, $Q^2=10\div25\;GeV^2$, the…
We suggest a new mechanism for the energy loss of fast heavy quarks in quark-gluon plasma. This mechanism is based on pion production caused by the anomalous chromomagnetic quark-gluon-pion interaction induced by strong topological…
The fragmentation of an unpolarized quark into a transversely polarized spin-1/2 particle is studied in the framework of a simple model. Special attention is payed to the gluon exchange which is incorporated in the gauge link of the…
In the low-energy regime light and strange baryons should be considered as systems of constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons as well as by vector and scalar mesons. The…
Pseudoscalar and axial neutral and charged pion-constituent quark coupling constants are investigated with nondegenerate quark masses in different kinematical points, off shell and on shell pions and constituent quarks. By considering a…
We calculate at two-loop order in chiral perturbation theory the electromagnetic corrections to the two-pion exchange nucleon-nucleon interaction that is generated by the isovector spin-flip $\pi\pi NN$ contact-vertex proportional to the…
The leading chiral contributions to the quark and gluon components of the proton spin are calculated using heavy-baryon chiral perturbation theory. Similar calculations are done for the moments of the generalized parton distributions…
We derive the pion-nucleon interaction in the framework of a new perturbative approach to QCD, based on the use of quark composites as fundamental variables. The composites with the quantum numbers of the nucleons are assumed as new…
Within the framework of Schwinger-Dyson and Bethe-Salpeter equations we investigate the importance of pions for the quark-gluon interaction. To this end we choose a truncation for the quark-gluon vertex that includes intermediate pion…