Accessing the pion 3D structure at US and China Electron-Ion Colliders

We present in this letter the first systematic feasibility study of accessing generalised parton distributions of the pion at an electron-ion collider through deeply virtual Compton scattering at next-to-leading order. It relies on a state-of-the-art model, able to fulfil by construction all the theoretical constraints imposed on generalised parton distributions. Strikingly, our analysis shows that quarks and gluons interfere destructively and that gluon dominance could be spotted by a sign change of the DVCS beam spin asymmetry.