Charge-exchange spin monopole modes

Using the self-consistent Hartree-Fock plus Tamm-Dancoff approximation with Skyrme interactions, the response of some β stable closed-shell nuclei to charge-exchange (t_±) spin monopole fields is estimated in the coordinate space. Both the isoscalar and isovector spin-correlation are included simultaneously. The excitation energy of t₊ giant resonance decreases considerably as the neutron excess (and consequently the nuclear mass number) increases, while that of t_- giant resonance remains nearly constant. We have tried to separate out the Gamow-Teller strength from the present charge-exchange spin monopole strength, both of which have the same quantum numbers, J^π=1⁺.