Exclusive processes in ep collisions at the EIC and LHeC: A closer look on the predictions of saturation models

The exclusive production of vector mesons and photons in ep collisions is investigated considering three phenomenological saturation models based on distinct assumptions for the treatment of the dipolehadron scattering amplitude. The latest high precision HERA data for the reduced and vector meson cross sections are used to update the saturation model proposed by Marquet Peschanski, and Soyez, which predicts that the saturation scale is dependent of the squared momentum transfer t. The MarquetPeschanski-Soyez predictions for the photon virtuality, energy and t dependencies of the exclusive rho, J/Psi, and deeply virtual Compton scattering cross sections are presented and a detailed comparison with the results derived using the impact parameter saturation models is performed. Our results indicate that a future experimental analysis of the t distribution d sigma/dt for exclusive processes in the kinematical range that will covered by the EIC and LHeC, considering the distinct photon polarizations and large values of t, will be able to discriminate between the distinct approaches for the QCD dynamics at high energies.