Spin-dipole excitations in 16O and tensor correlations

The multipole dependent effects induced by tensor correlations on the charge-exchange spin-dipole (SD) modes of the light nucleus 16O are studied within a Hartree-Fock (HF) plus self-consistent random-phase approximation (RPA), using Skyrme-type interactions. The role played by the triplet-even and triplet-odd tensor terms are examined separately to explain either the softening or hardening of the excitation energies of SD modes. The unperturbed and RPA summed strengths, calculated with and without the tensor force, are discussed and compared with the results of shell-model calculations.