COMPTON SCATTERING BY THE PROTON THROUGH THETA(CMS)=75-DEGREES AND 90-DEGREES IN THE DELTA-RESONANCE REGION

摘要

Differential cross sections for Compton scattering by the proton have been measured in the energy interval between 200 and 500 MeV at scattering angles of theta(cms) = 75 degrees and theta(cms) = 90 degrees using the CATS, the CATS/TRAJAN, and the COPP setups with the Glasgow Tagger at MAMI (Mainz). The data are compared with predictions from dispersion theory using photo-meson amplitudes from the recent VPI solution SM95. The experiment and the theoretical procedure are described in detail. It is found that the experiment and predictions are in agreement as far as the energy dependence of the differential cross sections in the Delta-range is concerned. However, there is evidence that a scaling down of the resonance part of the M-1+(3/2) photo-meson amplitude by (2.8+/-0.9)% is required in comparison with the VPI analysis. The deduced value of the M-1+(3/2)-photoproduction amplitude at the resonance energy of 320 MeV is: M-1+(3/2) = (39.6+/-0.4) x 10(-3) m(pi+)(-1). (C) 1997 Elsevier Science B.V. [References: 86]