# Partonic angular momentum in the nucleon's chiral periphery

## TL;DR

This paper investigates the distribution of partonic angular momentum in the nucleon's chiral periphery, revealing that orbital angular momentum dominates over spin at large transverse distances governed by chiral dynamics.

## Contribution

It provides a novel calculation of nucleon form factors and angular momentum densities at peripheral distances using chiral effective field theory and light-front formalism.

## Key findings

- Spin density is suppressed in the periphery.
- Orbital angular momentum dominates in the nucleon's chiral periphery.
- Field-theoretical AM density matches quantum-mechanical orbital AM of soft pions.

## Abstract

We study the nucleon's partonic angular momentum (AM) content at peripheral transverse distances $b = \mathcal{O}(M_\pi^{-1})$, where the structure is governed by chiral dynamics. We compute the nucleon form factors of the energy-momentum tensor in chiral effective field theory (ChEFT) and construct the transverse densities of AM at fixed light-front time. In the periphery the spin density is suppressed, and the AM is predominantly orbital. In the first-quantized representation of ChEFT in light-front form, the field-theoretical AM density coincides with the quantum-mechanical orbital AM density of the soft pions in the nucleon's periphery.