Pionic transparency in semi-exclusive electroproduction off nuclei

We investigate the early onset of pionic color transparency (πCT) observed at Jefferson Laboratory (JLAB) in semi-exclusive pion electroproduction reaction A(e,e'π+) off nuclei. In the present description the primary γ*p→π+n interaction is described very well both for the longitudinal and the transverse polarizations. For the final state interactions a coupled-channel treatment of the interactions of transmitted hadrons allows to go beyond the Glauber approximation. We show that a proper distinction between the soft hadronic and hard partonic components of the electroproduction amplitude is essential for a quantitative description of the measured nuclear transparency. The data are well reproduced if one assumes that point-like configurations are produced in the regime of hard deep-inelastic scattering (DIS) off partons and dominate the transverse channel