Exclusive measurements of the analyzing power and two spin-transfer observables for nucleon knockout from an ${}^{16}\mathrm{O}$ target are presented, at kinematic conditions chosen to emphasize interactions in the nuclear interior. The analyzing power data are substantially reduced in comparison with values calculated in the distorted wave impulse approximation (DWIA) using the free nucleon-nucleon interaction, particularly for knockout of the deeply bound ${1s}_{1/2}$ nucleons. Inclusion of density dependence for the interaction in the calculations improves the agreement with the data, but does not provide a satisfactory description for nucleon knockout from ${}^{16}\mathrm{O}.$ Spin-orbit distortions are shown to strongly affect the DWIA predictions of the ${1s}_{1/2}$ analyzing powers over most of the experimental kinematic range, but notably not near the points of negligible recoil momentum. Hence these data offer constraints on the optical potentials and independently on the two-body effective interaction.

• Received 7 August 1996

DOI:https://doi.org/10.1103/PhysRevC.57.1756