Entanglement, Trace Anomaly and Confinement in QCD
Abstract
We formulate confinement in QCD as an entropic surface phenomenon. Quark and gluon quantum information is localized on a transverse entangling two-sphere of radius ; at this radius the QCD vacuum -- partitioned by a hadron into interior and exterior regions -- reaches its maximal entanglement entropy. Lattice-QCD determinations of the scalar (trace) gravitational form factors fix both and the transverse trace-anomaly density , yielding a parameter-free slope and a mechanical entropy that grows linearly with rapidity . The entropy gradient changes sign at : it pushes colored degrees of freedom outward for and pulls them inward for , thereby localizing them on the codimension-2 entangling two-sphere (which, in the infinite-momentum frame, projects onto the transverse plane), the 'information wall'. This provides a high-energy (large-) entropic confinement diagnostic that complements -- rather than replaces -- Wilson's area-law criterion, which probes long-distance dynamics near the rest frame (). Imposing unitarity on an entropic ansatz for the amplitude yields . World data favor for elastic scattering and heavy-quark photoproduction, whereas photoproduction favors a softer . All extracted cross sections remain well below the Froissart--Martin bound. These results provide a confinement criterion quantified directly from non-perturbative QCD inputs, unifying the trace anomaly, entanglement entropy, and high-energy scattering within a single quantitative framework.
Cite
@article{arxiv.2507.00176,
title = {Entanglement, Trace Anomaly and Confinement in QCD},
author = {Kiminad A. Mamo},
journal= {arXiv preprint arXiv:2507.00176},
year = {2025}
}
Comments
v4: published version to Physical Review D (Letter)