Color transparency and short-range correlations in exclusive pion and nucleon removal reactions from nuclei

A relativistic and quantum mechanical framework to compute nuclear transparencies for pion and nucleon production reactions is presented. Final-state interactions for the ejected pions and nucleons are implemented in a relativistic Glauber eikonal approach. The proposed model can account for the color-transparency (CT) phenomenon and short-range correlations (SRC) in the nucleus. Results are presented for kinematics corresponding to completed experiments for A(γ,π+n) and A(e,e'π-), A(p,2p) and A(e,e'p). The influence of CT and SRC on the nuclear transparency is studied. Both the SRC and CT mechanisms increase the nuclear transparency. The two mechanisms can be clearly separated, though, as they exhibit a completely different dependence on the hard-scale parameter. Recent A(e,e'π+) results point towards the early onset of the CT phenomenon in pion production processes. The similarities in the trends and magnitudes of the computed nuclear transparencies compared to semi-classical models indicate that they are not subject to strong model dependences.