Hadronic deformation energy. II. Two-nucleon interaction

The MIT bag model for hadrons is treated in the static cavity approximation. The adiabatic deformation of a six-quark hadron with quantum numbers of the deuteron is studied in a configuration which permits the separation of two triplets with quantum numbers of the neutron and proton. The energy of the system is computed to second order in the gluon coupling and presented as a function of two choices of a single collective variable: a separation parameter for the nucleons and the baryonic quadrupole moment. The present study considers only interactions at short and intermediate range in a state with nuclear spins aligned in parallel along the deformation axis. It does not treat effects depending on nucleon momenta. The energy, when expressed in terms of a nuclear separation parameter, exhibits a soft repulsive core at short range due to a color-magnetic gluon interaction, and strong attraction in intermediate range due to a color-electric interaction.