Slow-proton production in semi-inclusive deep inelastic scattering off the deuteron and complex nuclei: Hadronization and final-state interaction effects

The effects of the final-state interaction in slow-proton production in semi-inclusive deep inelastic scattering processes off nuclei, A(e, e' p) X, are investigated in detail using the spectator and target-fragmentation mechanisms. In the former mechanism, a hard interaction on a nucleon of a correlated pair leads, by recoil, to the emission of the partner nucleon, whereas in the latter mechanism a proton is produced when the diquark, which is formed right after the gamma*-quark interaction, captures a quark from the vacuum. Unlike previous papers on the subject, particular attention is paid to the effects of the final-state interaction of the hadronizing quark with the nuclear medium using an approach based on an effective time-dependent cross section that combines the soft and hard parts of hadronization dynamics in terms of the string model and perturbative QCD, respectively. It is shown that the final-state interaction of the hadronizing quark with the medium plays a relevant role in both deuterons and complex nuclei. Nonetheless, kinematical regions where final-state interaction effects are minimized can be selected experimentally, which would allow one to investigate the structure functions of nucleons embedded in the nuclear medium. Likewise, regions where the interaction of the struck hadronizing quark with the nuclear medium is maximized can be found, which would make it possible to study nonperturbative hadronization mechanisms.