Coincidence analyzing-power measurements of the reaction 12C(p

Coincidence analyzing-power measurements or asymmetries {ital A}{sub {ital x}}{sup coinc}, {ital A}{sub {ital y}}{sup coinc}, and {ital A}{sub {ital z}}{sup coinc} are presented for the {sup 12}C({ital {rvec p}},{ital p}{prime}{gamma}){sup 12}C{sup *} (15.11 MeV) reaction. A polarized proton beam at 318 MeV was used and data were obtained for three mutually perpendicular directions of polarization. A scintillator hodoscope was used for detecting scattered protons and four BGO detectors for the 15.11-MeV {gamma} rays. Data are presented for eight azimuthal directions of the scattered protons around the beam direction, and for the polar angles averaged between 3.3{degree} and 11.2{degree}. The data are compared with both nonrelativistic and relativistic calculations. The average size of the asymmetries measured is somewhat less than both predictions and the results do not agree clearly with either prediction.