  Compton scattering from the proton was investigated at s=6.9 (GeV/c)**2 and
\t=-4.0 (GeV/c)**2 via polarization transfer from circularly polarized incident
photons. The longitudinal and transverse components of the recoil proton
polarization were measured. The results are in excellent agreement with a
prediction based on a reaction mechanism in which the photon interacts with a
single quark carrying the spin of the proton and in disagreement with a
prediction of pQCD based on a two-gluon exchange mechanism.
