Measurement of spin observables in theSi28(p→,p→ ’) reaction at 500 MeV and comparison with the distorted-wave impulse approximation

Analyzing power {ital A}{sub {ital y}} and spin-transfer observables {ital D}{sub {ital i}{ital j}} have been measured for 500-MeV proton inelastic scattering from {sup 28}Si. Measured values of the {ital D}{sub {ital i}{ital j}} for the 9.70-MeV 5{sup {minus}}, {ital T}=0, the 11.58-MeV 6{sup {minus}}, {ital T}=0, and the 14.35-MeV 6{sup {minus}}, {ital T}=1 states are reported at 17{degree} and 22{degree}; values of {ital A}{sub {ital y}} cover the range from about 10{degree} to 26{degree}. Nonrelativistic (NRIA) and relativistic (RIA) impulse-approximation calculations are compared with the data. The differences between the two types of calculations are generally small. The RIA yields excellent agreement with the {ital D}{sub {ital i}{ital j}} data for the 5{sup {minus}} state, and both RIA and NRIA do well for {ital D}{sub {ital i}{ital j}} data for the 6{sup {minus}}, {ital T}=0 state but poorly for the 6{sup {minus}}, {ital T}=1 state. For the {ital A}{sub {ital y}} data, both types of calculation give fairly good predictions for the 5{sup {minus}} and 6{sup {minus}}, {ital T}=1 states, but not for the 6{sup {minus}}, {ital T}=0 state. Comparison between theory and experiment for the combinations of observables {ital D}{sub {ital K}}, which are sensitive to individual termsmore » in the nucleon-nucleon interaction, indicates a possible need for medium corrections in the {ital T}=1 tensor and spin-orbit forces.« less