Gluon sivers and experimental considerations for TMDs

TL;DR

This paper discusses the challenges and considerations in measuring gluon transverse-momentum-dependent distribution functions (TMDs) at the Electron-Ion Collider, focusing on D meson pairs as a potential probe.

Contribution

It evaluates the feasibility of using D meson pairs to access gluon TMDs and discusses broader experimental issues for TMD measurements at the EIC.

Findings

D meson pairs can provide access to gluon TMDs.

Measuring gluon TMDs is challenging due to the rarity of D meson production.

Feasibility depends on experimental capabilities and analysis techniques.

Abstract

The study and characterisation of transverse-momentum-dependent distribution functions (TMDs) is a major goal of the Electron-Ion Collider (EIC) physics programme. The study of gluon TMDs poses a greater challenge than for quark TMDs in DIS measurements, as gluons do not directly couple to photons. The study of D meson pairs has been proposed to provide access to gluon TMDs, but is demanding due to the rarity of D production. Here, we discuss the feasibility of such a measurement, and touch upon wider issues to be considered when measuring TMDs at the EIC.