Are there infinitely many decompositions of the nucleon spin ?

TL;DR

This paper challenges the idea that there are infinitely many gauge-invariant ways to decompose the nucleon spin, questioning a popular approach in the field.

Contribution

It provides a critical analysis against the gauge-invariant-extension approach, arguing that it implies an unphysical infinity of decompositions.

Findings

Disputes the validity of the GIE approach in nucleon spin decomposition

Argues against the existence of infinitely many gauge-invariant decompositions

Clarifies conceptual issues in nucleon spin studies

Abstract

We argue against the rapidly spreading idea of gauge-invariant-extension (GIE) approach in the nucleon spin decomposition problem, which implies the existence of infinitely many gauge-invariant decomposition of the nucleon spin.