  We present predictions for the distribution of rapidity gaps in realistic
kinematics of future electron-ion colliders, based on numerical solutions of
the original Kovchegov-Levin equation and of its next-to-leading extension
taking into account the running of the strong coupling. We find that for the
rapidities we have considered, the fixed and the running coupling equations
lead to different distributions, rather insensitive to the chosen prescription
in the running coupling case. The obtained distributions for the fixed coupling
framework exhibit a shape characteristic of a recently proposed partonic
picture of diffractive dissociation already at rapidities accessible at future
electron-ion colliders. The modification of this shape in the running coupling
case can also be understood qualitatively from that picture. Our results
confirm the relevance of measurements of such observables for the microscopic
understanding of diffractive dissociation in the framework of quantum
chromodynamics.
