Low-virtuality leptoproduction of open-charm as a probe of the gluon Sivers function

TL;DR

This paper proposes using low-virtuality leptoproduction of open-charm at the EIC to directly probe the gluon Sivers function through measurable single-spin asymmetries, providing a new method to study gluon spin effects.

Contribution

It introduces a novel experimental approach to measure the gluon Sivers function via open-charm leptoproduction at the EIC, including predictions and decay-level analysis.

Findings

Predicted sizable single-spin asymmetries at EIC kinematics.

Asymmetry signals are preserved in muons from D-meson decays.

Provides theoretical estimates based on existing GSF fits.

Abstract

We propose low-virtuality leptoproduction of open-charm, $p^\uparrow l\to D^0+X$, as a probe of the gluon Sivers function (GSF). At leading-order, this process directly probes the gluon content of the proton, making detection of a trasverse single-spin asymmetry in the process a clear indication of a non-zero GSF. Considering the kinematics of the proposed future Electron-Ion Collider (EIC), we present predictions for asymmetry using fits of the GSF available in literature. We also study the asymmetry at the level of muons produced in D-meson decays and find that the asymmetry is preserved therein as well.