  We make predictions for the t-differential cross section of exclusive vector
meson production (EVMP) in electron-ion collisions, with the aim of comparing
DGLAP evolution to CGC models. In the current picture for the high-energy
nucleus, nonlinear effects need to be understood in terms of low-$x$ gluon
radiation and recombination as well as how this leads to saturation. EVMP
grants experimental access to the edge region of the highly-boosted nuclear
wavefunction, where the saturation scale for CGC calculations becomes
inaccessible to pQCD. On the other hand, DGLAP evolution requires careful
consideration of unitarity effects. The existing $J/{\psi}$ photoproduction
data in ep collisions provides a baseline for these theoretical calculations.
Under different small-$x$ frameworks we obtain a measurable distinction in both
the shape and normalization of the differential cross section predictions.
These considerations are relevant for heavy ion collisions because the initial
state may be further constrained, thus aiding in quantitative study of the
quark-gluon plasma.
