The 3D structure of the Nucleon in momentum space: TMD phenomenology

Abstract

I give a brief overview of our current understanding of the internal partonic 3D structure of nucleons in momentum space. I discuss some recent extractions of transverse-momentum-dependent distributions for quarks, whose analyses in the unpolarized case are reaching a theoretical precision comparable to collinear parton distribution functions. On the contrary, gluon transverse-momentum-dependent distributions are poorly known from a phenomenological point of view. I briefly review their general properties and sketch a recent model calculation covering all (un)polarized combinations at leading twist.

Comments: 11 pages, 5 multiple figures. Extended version of the proceedings of the conference "Diffraction and Low-x", 8-14 Sept. 2024, Hotel Tonnara Trabia, Palermo (Italy), to appear in Acta Physica Polonica B - Proc. Suppl