# Color entanglement effect in collinear twist-3 factorization

## TL;DR

This paper investigates the color entanglement effect in collinear twist-3 factorization, specifically analyzing its impact on transverse single spin asymmetries in proton-proton collisions, and demonstrates its origin through gauge link structures.

## Contribution

It provides a detailed analysis of color entanglement effects in collinear twist-3 factorization and confirms the results with a hybrid approach calculation.

## Key findings

- Color entanglement affects T-odd observables in collinear twist-3 framework.
- The gauge link structure reveals how gluon attachments induce entanglement.
- Results are consistent with hybrid approach calculations.

## Abstract

We study color entanglement effect for T-odd cases in collinear twist-3 factorization. As an example, we compute the transverse single spin asymmetry for direct photon production in pp collisions in pure collinear twist-3 approach. By analyzing the gauge link structure of the collinear gluon distribution on unpolarized target side, we demonstrate how color entanglement effect arises in the presence of the additional gluon attachment from polarized projectile. The result is consistent with that obtained from a hybrid approach calculation.