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Observation of the onset of color transparency in baryons would provide a new means of studying the nuclear strong force and would be the first clear evidence of baryons transforming into a color-neutral point-like size in the nucleus as predicted by quantum chromodynamics. Recent C(e,e′p) results from electron-scattering did not observe the onset of color transparency (CT) in protons up to spacelike four-momentum transfers squared, Q2=14.2 GeV2. The traditional methods of searching for CT in (e,e′p) scattering use heavy targets favoring kinematics with already initially reduced final state interactions (FSIs) such that any CT effect that further reduces FSIs will be small. The reasoning behind this choice is the difficulty in accounting for all FSIs. D(e,e′p)n, on the other hand, has well-understood FSI contributions from double scattering with a known dependence on the kinematics and can show an increased sensitivity to hadrons in point-like configurations. Double scattering is the square of the re-scattering amplitude in which the knocked-out nucleon interacts with the spectator nucleon, a process that is suppressed in the presence of point-like configurations and is particularly well-studied for the deuteron. This suppression yields a quadratic sensitivity to CT effects and is strongly dependent on the choice of kinematics. Here, we describe a possible Jefferson National Accelerator Facility (JLab) electron-scattering experiment that utilizes these kinematics and explores the potential signal for the onset of CT with enhanced sensitivity as compared to recent experiments. 

In light of the recent Jefferson Laboratory (JLab) data for the nuclear 12C(e,e′p) transparencies, calculations, obtained in a relativistic multiple scattering Glauber approximation, are discussed. The shell-separated 12C transparencies are shown and it is concluded that the p-shell nucleons are 75% more transparent than the s-shell ones. The presented comparisons between the calculations made here and the current 12C(e,e′p) data show no clear indication for the onset of color transparency when implemented within the color diffusion model with standard parameters. 

The paper proposes to study the onset of color transparency in hard exclusive reactions in the backward regime. Guided by the encouraging Jefferson Laboratory (JLab) results on backward π and ω electroproduction data at moderate virtuality Q2, which may be interpreted as the signal of an early scaling regime, where the scattering amplitude factorizes in a hard coefficient function convoluted with nucleon to meson transition distribution amplitudes, the study shows that investigations of these channels on nuclear targets opens a new opportunity to test the appearance of nuclear color transparency for a fast-moving nucleon.