English

Entanglement, Trace Anomaly and Confinement in QCD

High Energy Physics - Phenomenology 2025-12-19 v4 High Energy Physics - Theory Nuclear Theory

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 REER_{EE}; 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 REER_{EE} and the transverse trace-anomaly density ρh(REE)\rho_h(R_{EE}), yielding a parameter-free slope ch=8π2REE2ρh(REE)c_h = 8\pi^2 R_{EE}^2\,\rho_h(R_{EE}) and a mechanical entropy SEE(y)=chyS_{EE}(y)=c_h\,y that grows linearly with rapidity yy. The entropy gradient RSEE\partial_R S_{EE} changes sign at REER_{EE}: it pushes colored degrees of freedom outward for r<REEr<R_{EE} and pulls them inward for r>REEr>R_{EE}, thereby localizing them on the codimension-2 entangling two-sphere Σ=SREE2\Sigma_\perp = S^2_{R_{EE}} (which, in the infinite-momentum frame, projects onto the transverse plane), the 'information wall'. This provides a high-energy (large-yy) entropic confinement diagnostic that complements -- rather than replaces -- Wilson's area-law criterion, which probes long-distance dynamics near the rest frame (y0y\to 0). Imposing unitarity on an entropic ansatz for the amplitude yields σ(s)yδ\sigma(s)\propto y^{\delta}. World data favor δ=2\delta=2 for elastic pp(ppˉ)pp\,(p\bar p) scattering and heavy-quark photoproduction, whereas ϕ\phi photoproduction favors a softer δ=0.387\delta=0.387. 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.

Keywords

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)

R2 v1 2026-07-01T03:40:22.621Z