Pitfalls in looking for color transparency at intermediate energies.

Abstract

The problems and uncertainties in the search for color transparency at intermediate ${\mathrm{Q}}^{2}$ are considered. We show that conventional (optical) model [distorted wave impulse approximation (DWIA)] predicts a substantial change of the transparency, T, with ${\mathrm{Q}}^{2}$ in the kinematics of the NE-18 (e,e\ensuremath{'}p) experiment, while the color transparency phenomenon may lead to nearly ${\mathrm{Q}}^{2}$ independent T. In the case of A(p,2p) reaction we demonstrate that the conventional optical model well describes the 1 GeV A(p,2p) data but not the transparency observed at higher energies. We find also that DWIA (with or without color transparency) predicts strong dependence of T on the momentum of the struck nucleon which is consistent with the pattern of the Brookhaven National Laboratory A(p,2p) data at ${\mathrm{p}}_{\mathrm{N}}$=6 GeV/c and 10 GeV/c.