Gluon Sivers Function and Single Spin Asymmetry in $e+p^\uparrow \rightarrow e+J/\psi + X$

TL;DR

This paper investigates the gluon Sivers function by proposing to measure the transverse single spin asymmetry in $J/$ production during low virtuality electroproduction, predicting sizable asymmetries at various experimental facilities.

Contribution

It introduces a method to probe the gluon Sivers function through SSA measurements in charmonium production, utilizing the color evaporation model and existing gluon Sivers models.

Findings

Sizable SSA predicted at JLab, HERMES, COMPASS, and eRHIC energies.

Estimates based on the color evaporation model and current gluon Sivers models.

Provides a new experimental approach to study gluon spin effects.

Abstract

We propose measurement of transverse single spin asymmetry (SSA) in charmonium production as a probe of gluon Sivers function. We estimate SSA in low virtuality electroproduction of $J/\psi $ using color evaporation model of charmonium production and existing models of the gluon Sivers function and find sizable asymmetry at JLab, HERMES, COMPASS and eRHIC energies.