Energy Dependence of Nuclear Transparency in C(p,2p)Scattering

The transparency of carbon for $(p,2p)$ quasielastic events was measured at beam momenta ranging from 5.9 to $14.5\mathrm{GeV}/c$ at 90° c.m. The four-momentum transfer squared $\left(Q^2\right)$ ranged from 4.7 to $12.7(\mathrm{GeV}/c{)}^2$. We present the observed beam momentum dependence of the ratio of the carbon to hydrogen cross sections. We also apply a model for the nuclear momentum distribution of carbon to obtain the nuclear transparency. We find a sharp rise in transparency as the beam momentum is increased to $9\mathrm{GeV}/c$ and a reduction to approximately the Glauber level at higher energies.