Rho Meson Diffraction off Au Nuclei

Abstract

The STAR Ultra Peripheral Collisions program has collected a substantial sample of $\rho$ mesons and for the first time at RHIC energies it has been able to extract the distribution of momentum transfer t from diffractive elastic scattering off the Au ion. The resulting diffraction pattern is consistent with coherent scattering off a nuclear object the size of the Au nuclei. Measurements of this nature can offer insights and guidance to the ongoing preparations for the new electron ion programs.