Nuclear/Riken Theory Seminar

Perturbative QCD based on the Parton Model of the nucleon is a very successful theoretical approach to describe high-energy processes at particle accelerators and colliders. In particular, parton distribution functions are key ingredients of this approach and give information on the partonic substructure of the nucleon. As such they deliver a one-dimensional picture of how the parton momenta are distributed in the nucleon. In this talk extensions of the parton model are presented which provide access to more detailed information on the dynamics of partons in the nucleon. In particular observables involving transversely polarized nucleons are discussed. They can be described in terms of dynamical quark-gluon correlations which in turn can be studied at an Electron-Ion Collider. Another extension of the parton model takes into account the intrinsic transverse motion of the partons. In this approach - called Transverse Momentum Dependent (TMD) factorization - one can study three-dimensional distributions of the parton momenta. In addition, implications of the transverse motion of gluons in the nucleon will be discussed for LHC physics.