Final-state interactions in (e,e ' p) reactions with polarized nuclei

The cross section for coincidence, quasielastic proton knock-out by electro ns from a polarized K-39 nucleus is computed in DWIA using an optical poten tial in describing the wave function of the ejected nucleon. The dependence of the FSI on the initial polarization angles of the nucleus is analyzed a nd explained in a new, semi-classical picture of the reaction in which the nuclear transparency decreases as a function of the amount of nuclear matte r that the proton has to cross, thus providing a method for obtaining detai led information on its mean free path in finite nuclei. We propose a proced ure to find the best initial kinematical conditions for minimizing the FSI which will be useful as a guide for future experiments with polarized nucle i. (C) 1999 Elsevier Science B.V.