Gluon transverse momentum dependent correlators in polarized high energy processes

TL;DR

This paper explores gluon transverse momentum dependent correlators in high energy processes, focusing on their operator structure, gauge link complexities, and behavior in the small-x limit, providing insights into gluon TMDs for various polarizations.

Contribution

It introduces a detailed analysis of gluon TMD correlators, emphasizing the role of gauge links and Wilson loops, especially in the small-x regime, advancing understanding of gluon distributions.

Findings

Gauge links are non-unique for TMDs, affecting their structure.

Wilson loops become significant in the small-x limit.

Gluon TMDs vary with target polarization states.

Abstract

We investigate the gluon transverse momentum dependent correlators as Fourier transform of matrix elements of nonlocal operator combinations. At the operator level these correlators include both field strength operators and gauge links bridging the nonlocality. In contrast to the collinear PDFs, the gauge links are no longer unique for transverse momentum dependent PDFs (TMDs) and also Wilson loops lead to nontrivial effects. We look at gluon TMDs for unpolarized, vector and tensor polarized targets. In particular a single Wilson loop operators become important when one considers the small-x limit of gluon TMDs.