The influence of the nuclear medium upon the internal structure of a composite nucleon is examined. The interaction with the medium is assumed to depend on the relative distances between the quarks in the nucleon consistent with the notion of color neutrality, and to be proportional to the nucleon density. In the resulting description the nucleon in matter is a superposition of the ground state...

Conceptual problems of unified two-nucleon force models are discussed. The force models are based on the pion-nucleon vertex and attempt a description of the nucleon-nucleon interaction below and above pion threshold. The conceptual problems arise from the nucleon renormalization due to pionic degress of freedom. Keeping channels with a single pion only no renormalization procedure can be given...

A b s t r a c t The radius of interaction between the struck proton and spectator nucleons is close to the radius of short-distance two-nucleon correlations in nuclear matter, which makes final state interaction (FSI) an important background to production of protons with large missing momentum. We present a simple classification of the dominant FSI effects in 4 He(e, e ′ p) scattering and ident...

We consider S0 pairing in infinite neutron matter and nuclear matter and show that in the lowest order approximation, where the pairing interaction is taken to be the bare nucleon-nucleon (NN) interaction in the S0 channel, the pairing interaction and the energy gap can be determined directly from the S0 phase shifts. This is due to the almost separable character of the nucleonnucleon interacti...

We study the short-range nucleon-nucleon interaction in a nonrelativistic chiral constituent quark model by diagonalizing a Hamiltonian containing a linear confinement and a Goldstone boson exchange interaction between quarks. A finite six-quark basis obtained from single particle cluster model states was previously used. Here we show that the configurations which appear naturally through the u...

The complex Kohn variational principle and the (correlated) hyperspherical harmonics method are applied to study the proton–deuteron elastic scattering at energies above the deuteron breakup threshold. Results for the elastic cross section and various elastic polarization observables have been obtained by taking into account the long–range effect of the Coulomb interaction and using a realistic...

By solving the Schrödinger equation for the three-quark system in the hyperspherical harmonic approach, we have studied the low energy part of the nucleon and ∆ spectra using a quark-quark interaction which reproduces the nucleon-nucleon phenomenology. The quark-quark hamiltonian considered includes, besides the usual one-gluon exchange, pion and sigma exchanges generated by the chiral symmetry...

Based on a quark cluster model for the non-strange sector that reproduces reasonably well the nucleon-nucleon system and the excitation of the ∆ isobar, we generate a nucleon-∆ interaction and present the predictions for the several isospin two channels. The only attractive channels are 0+ and 0, but not attractive enough to generate a resonance. If a resonance is artificially generated and is ...

The s-s̄ asymmetry in nucleon sea is an important observable for understanding nucleon structure and strong interaction. There have been many theoretical attempts on this subject and recently on its relation to the “NuTeV anomaly”. Calculations with different theoretical frameworks lead to different conclusions. Here assuming a newly proposed penta-quark configuration for the s-s̄ asymmetry in nu...