Theoretical cross-sections of pion production by 450 MeV protons on various nuclei.

An expression for the differential cross-section of pion production by protons on nuclei is built up using the impulse approximation. It assumes the knowledge of free nucleon-nucleon pion production and takes account of the internal nucleon momentum distribution, the Coulomb potential, and the absorption effects of the incoming protons and outgoing pions. Calculation for the special case of 450 MeV incident protons is carried out to demonstrate the success of our model and the A-dependence of the cross-section is found to agree rather well with experiment. It turns out that the pion production process is dominated by the pion absorption and the relative proportion of protons and neutrons inside the nucleus is a significant factor.Science, Faculty ofPhysics and Astronomy, Department ofGraduat