Scale-anomaly-induced binding pressure in hadrons

TL;DR

This paper investigates how the QCD scale anomaly influences the internal pressure distribution of hadrons, revealing that it universally induces negative binding pressure across different hadron types and models.

Contribution

It demonstrates that the scale anomaly universally causes negative binding pressure in hadrons, based on model-independent gravitational form factors and pressure distribution analysis.

Findings

Scale anomaly induces negative binding pressure in hadrons.

The effect is universal across hadron types and models.

Pressure distributions analyzed in instant and light-front forms.

Abstract

The effect of the QCD scale anomaly on the internal pressure distribution of hadrons is studied based on the trace-traceless decomposition of the energy-momentum tensor. Using recent model-independent results of gravitational form factors as input, the pressure distributions of both pions and nucleons are analyzed in the instant form and the light-front form. It is found that, in all cases, the scale anomaly dominantly generates the negative binding pressure. This result suggests that the phenomenon is a universal feature, independent of models, types of hadrons, and the choice of form.