Speaker: dr hab. Herve Moutarde (IRFU, CEA, Université Paris-Saclay)
Three-dimensional hadron structure constitutes a significant part of the physics program to be investigated on future electron-ion colliders. This topic has benefited from two decades of experimental investigations which mostly provided direct constraints on quark distributions. This contrasts with gluon distributions which can be accessed either indirectly through careful phenomenological analysis of accurate measurements, or directly by probing the adequate kinematic domain. In both cases a unified theoretical description is required to provide a full quantitative understanding of the 3D parton structure of hadrons.
After a brief reminder of what make generalized parton distributions a unique tool to reveal the structure of hadrons, we will discuss the constraints provided by existing measurements and review recent theoretical developments. We will highlight what can be expected from future electron-ion colliders with the specific example of nucleon internal pressure distributions and the 3D structure of the pion. We will also explain why and how these developments naturally fit in the European-wide collaborative effort of the project STRONG-2020 funded within the H2020 program.