On the behaviour of R(pA) at high energy

Abstract

We discuss the behaviour of R(pA), the ratio of the unintegrated gluon distribution of a nucleus over the unintegrated gluon distribution of a proton scaled up by A^{1/3}, at high energy and fixed coupling. We show that R(pA) exhibits a rising gluon shadowing with growing rapidity, approaching 1/A^{1/3} at asymptotic rapidity, which means total gluon shadowing due to gluon number fluctuations or Pomeron loops.

Comments: 6 pages, 3 figures: To appear in the proceedings of 12th International Conference on Elastic and Diffractive Scattering; Forward Physics and QCD, DESY, Hamburg, Germany, 21-25 May 2007