Compton scattering by the proton through θcms = 75° in the Δ-resonance region

Abstract Using the tagged-photon beam of MAMI (Mainz) differential cross-sections for Compton scattering by the proton through θ cms = 75° have been measured for the Δ-resonance region from 200 to 410 MeV. The data put a new constraint on the M 1+ 3 2 photoproduction amplitude in the resonance, |M 1+ 3 2 | = (39.6 ± 0.4) · 10 −3 m π + −1 at 320 MeV, which is (2.8 ± 0.9) % less than given by the recent analysis SM95 of the Virginia group.