Investigating the Transverse Single Spin Asymmetry in the Inelastic $J/\Psi$ photoproduction in $p^\uparrow p$ and $p^\uparrow A$ collisions

TL;DR

This paper explores the potential of using inelastic $J/ ext{Psi}$ photoproduction in polarized proton and proton-nucleus collisions at RHIC to probe the gluon Sivers function through transverse single spin asymmetry measurements.

Contribution

It introduces a method to investigate the gluon Sivers function via $J/ ext{Psi}$ photoproduction and predicts measurable asymmetries at RHIC energies, highlighting the process's experimental feasibility.

Findings

Large cross sections predicted, indicating feasible experimental analysis.

Strong dependence of asymmetry on the gluon Sivers function model.

Asymmetry can be effectively probed at forward rapidities.

Abstract

In this paper we propose to investigate the transverse single spin asymmetry in the inelastic $J/\Psi$ photoproduction in $p^\uparrow p$ and $p^\uparrow A$ collisions at RHIC energies. At leading order this process probes the gluon Sivers function. We predict large values for the cross sections, which indicates that its experimental analysis is, in principle, feasible. The rapidity dependence of the single spin asymmetry is presented. We obtain that the asymmetry is strongly dependent on the model used for the gluon Sivers function and that it can be probed by the analysis of the $J/\Psi$ production at forward rapidities. Our results indicate that a future experimental analysis of this process can be useful to constrain the gluon Sivers function.