MEASUREMENT OF THE C-12(GAMMA,PI(0)) REACTION NEAR-THRESHOLD

The total cross section and pion angular distributions for the reactio n C-12(gamma, pi(0)) have been measured within 25 MeV of threshold usi ng tagged photons and a large acceptance pi(0) spectrometer at the Sas katchewan Accelerator Laboratory (SAL). The total cross section is in agreement with earlier measurements from Saclay and Mainz. The element ary P-wave photoproduction amplitude P-3((+)) has been determined from a distorted wave impulse-approximation analysis of the nuclear data a nd compares favorably with the corresponding free-nucleon amplitude in the threshold region. The incoherent contribution from the 4.43 MeV ( 2(+)) state has been deduced from the pion angular distributions and i s in agreement with previous experimental estimates.