l - th / 0 30 80 59 v 1 2 2 A ug 2 00 3 Scalar three - body force and the properties of the three - nucleon system with the dressed - bag model for NN interaction

Scalar three-body force and the properties of the three-nucleon system with the dressed-bag model for N N interaction. Abstract. A multi-component formalism is developed to describe three-body systems with nonstatic pairwise interactions and non-nucleonic degrees of freedom. The dressed-bag model for N N interaction based on the formation of an intermediate six-quark bag dressed by a σ-field is applied to the 3N system, where it results in a new three-body force between the six-quark bag and a third nucleon. Concise variational calculations of 3N bound states are carried out in the dressed-bag model including the new three-body force. It is shown that this three-body force gives at least half the 3N total binding energy, while the weight of non-nucleonic components in the 3 H and 3 He wavefunctions can exceed 10%. The new force model provides a very good description of 3N bound states with a reasonable magnitude of the σN N coupling constant. The model can serve as a natural bridge between dynamicaldescription of few-nucleon systems and the very successful Walecka approach to heavy nuclei and nuclear matter.