Higher-shell corrections for systems with one and two valence nucleons: A spin-orbit and tensor interaction analysis

It is shown that when higher-shell admixtures are included for systems with two valence particles or holes, there are effects which are quite different from those for one-valence-nucleon systems. For example, for nuclei with one valence particle or hole, there is no first-order correction for the magnetic dipole moment or the Gamow-Teller transition amplitude. However for nuclei with two valence particles or holes, one can get substantial corrections. The effects of the tensor and spinorbit interactions in core renormalization are emphasized. We find that in Li, the spin-orbit interaction causes the quadrupole moment of the J=1 ground state to be positive, but the tensor interaction causes it to be negative. The G-matrices derived from realistic interactions are employed in these calculations.