We have made simultaneous measurements of singles ($\overrightarrow{p}, {\overrightarrow{p}}^{\prime }$) spin-transfer observables and coincident ($\overrightarrow{p}, p^{\prime }\gamma$) yields and asymmetries for the 15.11 MeV, $1^{+}$, $T=1\mathrm{}$ state in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, at an incident proton bombarding energy of 200 MeV. Data were taken at four proton scattering angles ranging from ${\theta }_p^{\mathrm{c}.\mathrm{m}.\mathrm{}}=5.5\mathrm{}° \mathrm{to} 16.5°$. Both vertical (normal to the reaction plane) and horizontal (in-plane) incident beam polarizations were used, which allowed us to extract 16 different observables for this transition. In particular, using the ($\overrightarrow{p}, p^{\prime }\gamma$) reaction, we measured the sideways and longitudinal analyzing powers, $D_{0S}$ and $D_{0L}$, which vanish identically in the ($\overrightarrow{p}, p^{\prime }$) reaction. Detailed comparisons of all observables to calculations done in both relativistic and nonrelativistic formalisms are presented. Surprisingly, a relativistic description in which knock-on exchange processes are not explicitly included provides the best overall agreement with the data.

• Received 21 July 1995

DOI:https://doi.org/10.1103/PhysRevC.52.2559