ATOMIC-NUMBER DEPENDENCE OF THE ASYMMETRY OF THE CROSS-SECTIONS FOR INCLUSIVE (GAMMA,PI) REACTIONS

The asymmetry of the cross sections for inclusive photoproduction of charged pions has been studied as a function of the atomic number of the target for the nuclei Li-6, Li-7, Be-9, C-12, Al-27, and W-184. The pion emission angle was 90-degrees in the laboratory frame. The peak in the coherent bremsstrahlung was at an energy of 350 MeV. The asymmetry decreases from 0.57 at A = 1 to 0.26 at A congruent-to 20 and then remains essentially constant at higher values of A.