Asymmetry Measurements for Neutral Pion and Positive Pion Photoproduction by Linearly Polarized Gamma Rays in the Energy Range 400-900 MeV,

Abstract : The asymmetry ratio A = sigma normal - sigma parallel/sigma normal + sigma parallel has been measured using linearly polarized gamma-rays for neutral pion photoproduction. For the reaction gamma + P yields n + Positive pion, measurements were taken for theta sub cm = 135 degrees at gamma-ray energies ranging from 390 to 909 MeV. For the reaction gamma + P yields P + neutral pion, measurements were taken for theta sub cm = 60 degrees and 90 degrees at gamma-ray energies ranging from 426 to 918 MeV. (Author)