Gauge Invariant Descriptions of Gluon Polarizations Revisited

TL;DR

This paper explores gauge invariant methods to describe gluon polarization, proposing new formulations for gauge invariant gluon and photon spin descriptions, and relating these to parton distributions and laser mode spins.

Contribution

It introduces novel gauge invariant expressions for gluon and photon spins and demonstrates their application to laser modes and parton distributions.

Findings

Gauge invariant angular momentum currents can be built from gauge variant Noether currents.

New expressions for pure gauge fields enable gauge invariant descriptions of gluon and photon spins.

Gauge invariant operators relate to parton distributions from Dirac variables.

Abstract

We examine the feasibility of gauge invariant descriptions of the gluon polarization following the proposal that a gauge field can be decomposed into its physical part and its pure gauge part. We show that gauge invariant angular momentum currents can be constructed from summations of gauge variant Noether currents. We present novel expressions of the pure gauge field, which are used to formulate gauge invariant descriptions of the gluon spin and the photon spin. We show that the gauge invariant extension of the Chern-Simons current can describe the spins of the Laguerre-Gauss laser modes. We also discuss the relation of gauge invariant operators and the parton distributions constructed from Dirac variables.