Transparency of nuclei and mean free path of protons and pions in nuclear matter at intermediate energies

In the second resonance region of photon energies, the differential yields of neutral and charged pions are measured in the (γ, πp) reactions on Li, C, and Al nuclei versus the proton energy and the azimuthal angle of pion emission. These experimental data are analyzed on the basis of a model that takes into account both single and double quasifree pion photoproduction. This results in deriving the mean free paths of protons and neutral and charged pions and in estimating the transparency of the participant nuclei.