NUCLEAR TRANSPARENCY IN QUASI-ELASTIC A(E,E'P) - INTRANUCLEAR CASCADEVERSUS EIKONAL APPROXIMATION

The problem of nucleon propagation through the nuclear medium in quasi elastic A(e,e'p) reactions is discussed in the kinematic range 1 less than or equal to Q(2) less than or equal to 7 (GeV/c)(2). Experimental data are available from SLAC, BATES, and, recently, also from TJNAF. The coefficient of nuclear transparency is calculated for each Q(2) in the framework of the intranuclear cascade model (INC) and of the eiko nal approximation (EA). The former has the capability of directly impl ementing the detector acceptances giving a very detailed analysis of t he different observables. The latter, essentially based on an exclusiv e mechanism, contains explicit information about the dependence on the target shell structure. The predictions of both models are in good ag reement with each other. The INC model reproduces the experimental dat a quite well in the measured range. The EA gives an explanation of the Q(2) behavior of the transparency coefficient as a kinematic effect r elated to the superposition of contributions from each target shell. [ S0556-2813(98)03405-0].