ISOVECTOR SPIN-LONGITUDINAL AND SPIN-TRANSVERSE RESPONSE OF NUCLEI

The sum and energy-weighted sum of isovector spin-longitudinal and -tr ansverse response of H-2, He-4, O-16, and nuclear matter are studied w ith realistic models of nuclear forces. The results for O-16 are compa red with those obtained using effective interactions and the random-ph ase approximation. The responses of H-2 and the Laplace transforms of the responses of H-2 and He-4 are also calculated. We confirm the earl ier predictions that nuclear forces enhance the isovector spin-longitu dinal response over the spin-transverse. However, we find that they al so push the strength of both these responses to higher energies. Indic ations of the predicted enhancement have not been observed in p over a rrow pointing right, n over arrow pointing right experiments on C-12 a nd Ca-40 recently carried out at Los Alamos. We find that conventional nuclear theory predicts a measurable enhancement in H-2 and a signifi cant enhancement in He-4. Since many properties of these few-body nucl ei are well explained with realistic nuclear forces an experimental ve rification of the enhancement, or its absence, in H-2 and He-4 will be very interesting.