Accessing the distribution of linearly polarized gluons in unpolarized hadrons

TL;DR

This paper discusses how linearly polarized gluons in unpolarized hadrons can be accessed via cos(2 phi) asymmetries in heavy quark pair or dijet production, with estimates for future collider experiments like EIC and LHeC.

Contribution

It provides the first estimates of maximum asymmetries for probing linearly polarized gluons at future electron-hadron colliders.

Findings

Maximum asymmetries estimated for EIC kinematics.

Proposes cos(2 phi) asymmetries as a safe probe.

Highlights potential of future colliders for gluon polarization studies.

Abstract

Gluons inside unpolarized hadrons can be linearly polarized provided they have a nonzero transverse momentum. The simplest and theoretically safest way to probe this distribution of linearly polarized gluons is through cos(2 phi) asymmetries in heavy quark pair or dijet production in electron-hadron collisions. Future Electron-Ion Collider (EIC) or Large Hadron electron Collider (LHeC) experiments are ideally suited for this purpose. Here we estimate the maximum asymmetries for EIC kinematics.