Color Transparency in Semi-Inclusive Electroproduction of rho Mesons

Abstract

We study the electroproduction of rho mesons in nuclei at intermediate energies, deriving a treatment of the energy lost by the rho in each step of multiple-scattering. This enables a close match between calculations and the experimental kinematic conditions. A standard Glauber calculation is presented, and then the effects of color-transparency are included. The influence of poor experimental resolution on the extracted transparency is assessed. The effects of $\rho$ meson decay inside the nucleus are examined, and are typically about 5 percent at most. This effect disappears rapidly as $Q^2$ increases from about 1 to 3 GeV$^2$, causing a rise in the transparency that is not attributable to color transparency. The size of color transparency effects for C and Fe nuclei is studied for values of $Q^2$ up to 10 GeV$^2$. The detailed results depend strongly on the assumed value of the $\rho N$ cross section. The overall effects of color transparency are greater than about 10 % for both nuclear targets if $Q^2$ is greater than about 5 GeV$^2$.