Work

Pseudogauge ambiguity in the distributions of energy density, pressure, and shear force inside the nucleon

Year: 2026

Type: article

Abstract: We study the spatial distributions of pressure, energy density, and shear forces inside the nucleon within the two-flavor Skyrme model including vector mesons. This framework has the advantage that nucleon configurations can be stabilized without the Skyrme term. In contrast to the model without vector mesons, however, we realize that the energy-momentum tensor (EMT) becomes pseudogauge dependent. We explicitly demonstrate that all these distributions differ between the canonical and Belinfante forms of the EMTs. We identify the pseudogauge ambiguity as originating from nonvanishing surface terms associated with spin currents generated by the vector-meson field strength tensors. Furthermore, we show that the pressure and shear-force distributions in the canonical EMT develop singularities at the nucleon center, whereas the corresponding Belinfante distributions remain finite. Finally, we discuss the implications of pseudogauge dependence for extracting the confining force and for constructing the equation of state inside the nucleon.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/mkyh-n8st

Authors: Kenji Fukushima, Tomoya Uji

Institution: The University of Tokyo

Language: English

Topic: Quantum Chromodynamics and Particle Interactions

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: University of Tokyo, Japan Society for the Promotion of Science

Award: G2284962741