TMDs and SSAs in hadronic interactions

Abstract

We present an overview on the current experimental and phenomenological status of transverse single spin asymmetries (tSSAs) in proton-proton collisions. In particular, we focus on large-$p_T$ inclusive pion, photon, jet, pion-jet production and Drell-Yan processes. For all of them theoretical estimates are given in terms of a generalised parton model (GPM) based on a transverse momentum dependent (TMD) factorisation scheme. Comparisons with the corresponding results in a collinear twist-3 formalism and in a modified GPM approach are also made. On the experimental side, a selection of the most interesting and recent results from RHIC is presented.

19 pages, 20 figures with 28 ps files, uses svjour.cls. Invited review contribution to the Special Issue on "3D Structure of the Nucleon" to be published in the European Physical Journal A - Hadrons and Nuclei