POLARIZED COMPTON-SCATTERING FROM THE PROTON

New precision measurements of cross sections and polarization asymmetr ies in thr p(<(gamma)over bar>,gamma p) reaction at 90 degrees c.m. ar e presented for incident energies between 213 and 333 MeV. A long-stan ding problem with earlier experiments that appeared to violate unitari ty at the peak of the Delta is resolved. Data are compared to theories based on baryon resonance structure and to dispersion relations. Rece nt calculations using the proton polarizabilities are closest to the d ata, although inconsistencies are observed near the Delta resonance.