Gluon distribution functions for very large nuclei at small transverse momentum

Abstract

We show that the gluon distribution function for very large nuclei may be computed for small transverse momentum as correlation functions of an ultraviolet finite two-dimensional Euclidean field theory. This computation is valid to all orders in the density of partons per unit area, but to lowest order in ${\ensuremath{\alpha}}_{s}$. The gluon distribution function is proportional to $\frac{1}{x}$, and the effect of the finite density of partons is to modify the dependence on the transverse momentum for small transverse momenta.