Multi-scattering effects in (e,e'p) knockout

Multistep direct scattering of the ejectile proton is considered in (e,e'p) reactions in the quasi-free region as an improvement over the usual treatment of final-state interactions by means of an optical potential. The theory is applied to 40Ca(e,e'p) as a case example. Important contributions of two- and three-step processes are found at high missing energy and momentum in agreement with the experimental trend.