Process dependence of the gluon Sivers function in inclusive $pp$ collisions: phenomenology

Abstract

Within the so-called color gauge invariant generalized parton model, a TMD scheme including initial- (ISI) and final-state (FSI) interactions, we present a phenomenological analysis of available SSA data for pion and $D$-meson production in $pp$ collisions. This allows us, for the first time, to put a preliminary constraint on the two universal types of gluon Sivers function entering the model. Predictions for SSAs in $J/ψ$ and direct photon production, as well as a comparison with the simpler generalized parton model (without ISIs and FSIs), are also presented.

7 pages, 6 figures (11 plots); to appear in the Proceedings of the 23rd International SPIN Symposium (SPIN 2018), Ferrara, Italy, September 10-14, 2018