Spin excitations in light nuclei: The $$(\vec p,\vec p')$$ reaction on40Ca

We present a microscopic analysis of the nuclear spin response to proton excitation by examining the specific case of the40Ca\((\vec p,\vec p')\) reaction. Recent results at LAMPF indicate an interesting trend of a decrease in spin dipole strength and an increase in quadrupole strength when the proton momentum transfer is increased. We show that these effects are consistent with Random Phase Approximation (RPA) results and that, furthermore, the experimental spin response can be used to yield unequivocal information on the strength of the spin-isospin component of the nuclear interaction.