Quark model description of the N-N system: Momentum distributions, structure functions, and the EMC effect.
/ Abstract
We employ a relativistic quark bag picture, the chromodielectric soliton model, to discuss the quarks` symmetry structure and momentum distribution in the {ital N}-{ital N} system. Six-quark clusters are constructed in a constrained mean-field calculation. The corresponding Hamiltonian contains not only an effective interaction between the quarks and a scalar field, which is assumed to parametrize all nonperturbative effects due to the nonlinearity of QCD, but also quark-quark interactions mediated through one-gluon exchange. We also evaluate the quark light-cone distribution functions, characterizing inclusive deep-inelastic lepton scattering, for the nucleon as well as for the six-quark structures. We find a competition between a softening of the quarks` momenta through the increase of the confinement volume, and a hardening via the admixture of higher symmetry configurations due to the color-electrostatic one-gluon exchange. These findings suggest an unexpected absence of many-nucleon, multiquark effects, even though six-quark structures should represent a nonnegligible part of the nuclear ground state.
Journal: Physical review. C, Nuclear physics