Implications of spin-current couplings for PA in inelastic proton scattering

Nonlocal spin-dependent couplings in the effective nucleon-nucleon interaction are shown to probe current spin correlations in inelastic nuclear excitations. Together, these couplings and correlations provide an important dynamical source of polarization-analyzing-power differences observed in inelastic proton scattering. This is illustrated explicitly by schematic calculations for 0+'1+ and 0+'0- transitions. More realistic distorted-wave impulse approximation calculations have been made for the 0+'1+ transition in Zr90 at Ex=8.9 MeV which support the more transparent schematic considerations. Distorted-wave impulse approximation calculations are also compared with experimental (p,p') data for the two lowest 1+ excitations in C12. For isovector 0+'1+ transitions these nuclear structure spin current correlations also enter 2 decay through the "induced tensor" couplings, and this relationship is used to help identify the nonlocality in the nucleon-nucleon effective interaction.