Illuminating Nucleon Gluon Interference via Calorimetric Asymmetry

TL;DR

This paper introduces a novel calorimetric method to detect linearly polarized gluons inside unpolarized nucleons by analyzing azimuthal energy flow correlations, offering a radiation-free, symmetry-preserving signature.

Contribution

The paper proposes a new approach to measure linearly polarized gluons using azimuthal asymmetry analysis in lepton-nucleon scattering, which is robust against radiation effects.

Findings

Identifies a $ ext{cos}(2 ext{phi})$ asymmetry as a signature of gluon polarization.

Demonstrates the method's invariance under all orders of perturbation.

Shows the approach is free from radiation contamination.

Abstract

We present an innovative approach to the linearly polarized gluons confined inside the unpolarized nucleon in lepton-nucleon scattering. Our method analyzes the correlation of energy flows at azimuthal separations $\phi$. The interference of the spinning gluon with both positive and negative helicities translates into a $\cos(2\phi)$ asymmetry imprinted on the detector. Unlike the conventional transverse momentum dependent (TMD) probes, the $\cos(2\phi)$ asymmetry in this approach is preserved by rotational symmetry, holds to all orders, and is free of radiation contamination, thus expected to provide the exquisite signature of the nucleon linearly polarized gluons.