Speaker
Description
We present the results of two experimental programs at the Alternating Gradient Synchrotron of Brookhaven National Lab, to measure the nuclear transparency of nuclei via the quasi-elastic A(p,2p) scattering process near 90° in the pp center of mass. Data was taken at effective incident momenta ranging from 5.0 to 15.8 GeV/c (taking into account the Fermi motion of the target proton in the nucleus), corresponding to 4.8 < Q2 < 12.7 GeV/c2. We discuss the experimental techniques of the two programs, and show our finding that the A(p,2p) nuclear transparency, unlike A(e,e’p) data, is incompatible with a constant value versus energy as predicted by Glauber calculations. We further present the observed scattering angle and A dependence of the data, and describe the possible theoretical explanations of our observed trends.
