A New Derivation of the Twist-3 Gluon Fragmentation Contribution to Polarized Hyperon Production

TL;DR

This paper introduces a new covariant gauge-based method for deriving the twist-3 gluon fragmentation contribution to hyperon polarization in proton-proton collisions, clarifying the theoretical structure and eliminating ghost-like terms.

Contribution

It presents a novel derivation approach using Ward-Takahashi identities, improving the understanding of twist-3 contributions in polarized hyperon production.

Findings

Robust construction of the general cross section formula.

Clear explanation for the absence of ghost-like terms.

Enhanced theoretical understanding of twist-3 gluon fragmentation.

Abstract

A novel method of formulating the twist-3 gluon fragmentation function contribution to hyperon polarization in the proton-proton collision is presented. The method employs a covariant gauge and takes full advantage of the Ward-Takahashi identities before performing the collinear expansion. It provides a robust way of constructing the general cross section formula, and also a clear understanding for the absence of the ghost-like terms in the twist-3 cross section in the leading order with respect to the QCD coupling constant.