Color Transparency after the Ne18 and E665 Experiments

Abstract

The 1993 witnessed two major news in the field of color transparency (CT): i) no effect of CT was seen in the SLAC NE18 experiment on $A(e,e'p)$ scattering at virtualities of the exchanged photon $Q^{2} \lsim 7$ GeV$^{2}$, ii) strong signal of CT was observed in the Fermilab E665 experiment on exclusive $\rho^{0}$-meson production in deep inelastic scattering in the same range of $Q^{2}$. Both are good news and rule in CT, since this striking difference in the onset of CT for two reactions was predicted theoretically, and we review the theory of both reactions and the origin of this difference. We discuss an importance of final state interaction effects for the theoretical interpretation of the NE18 data. We comment on possible CT effects in the $^{4}He(e,e'p)$ interactions at CEBAF.