The gluon Sivers function and its process dependence from RHIC data

Abstract

We present a phenomenological analysis of available data on single spin asymmetries for pion and $D$ meson production in proton-proton collisions at RHIC within the color gauge invariant generalized parton model (CGI-GPM), which includes initial (ISIs) and final (FSIs) state interactions in a transverse momentum dependent formalism. This study allows us, for the first time, to put preliminary constraints on the two independent gluon Sivers functions entering the model. We also present a comparison with the simpler generalized parton model (without ISIs and FSIs).

Comments: 6 pages, 3 figures, to appear in the Proceedings of the 27th International Workshop on Deep Inelastic Scattering and Related Subjects (DIS 2019), Torino (Italy), 8-12 April 2019