Nuclear enhancement and suppression of diffractive structure functions at high energies

Abstract

We compute diffractive structure functions for both protons and nuclei in the framework of Color Glass Condensate models with impact parameter dependence. These models have previously been shown to provide good agreement with inclusive F_2 measurements and exclusive vector meson measurements at HERA. For nuclei, they provide good (parameter free) agreement with the inclusive F_2 data. We demonstrate good agreement of our computations with HERA measurements on inclusive diffraction. We extend our analysis to nuclei and predict the pattern of enhancement and suppression of the diffractive structures functions that can be measured at an Electron Ion Collider. We discuss how the impact parameter dependence crucially affects our analysis, in particular for large invariant masses at fixed Q^2.