Holography and two phases of the QCD vacuum

TL;DR

This paper explores the application of the holographic principle to quantum chromodynamics (QCD), analyzing two distinct gluon vacuum phases and their relation to classical and quantum descriptions via holography.

Contribution

It provides a novel perspective on the QCD vacuum by relating the hadronic and plasma phases to holographic duality and classical solutions in Yang-Mills theory.

Findings

Identification of two gluon vacuum phases with different symmetries

Insights into gauge symmetries from classical Yang-Mills solutions

Connection between holography and QCD vacuum structure

Abstract

The holographic principle is often (and hastily) attributed to quantum gravity and domains of the Planck size. Meanwhile it can be usefully applied to problems where gravitation effects are negligible and domains of less exotic size. The essence of this principle is that any physical system can be taken to be either classical, placed in a D+1-dimensional spacetime, or quantum-mechanical, located in its D-dimensional boundary. For example, one believes that a hydrogen atom is a typical quantum system living in a four-dimensional spacetime, but it can also be conceived as a classical system living in a five-dimensional embracing spacetime. The subnuclear realm is more intricate since the gluon vacuum reveals two phases, the hadronic and plasma phases. They differ in energetics and symmetry. Moreover, the classical four-dimensional picture is pertinent to the behavior of constituent quarks while the plasma phase is expected to be grasped by standard four-dimensional QCD. The relation between the holographic standpoint and the symmetry treatment of these two phases is outlined. Exact retarded solutions to the classical SU(N) four-dimensional Yang-Mills equations with the source composed of several point-like colored particles is considered. Features of these solutions in the large-N limit provide insight into the gauge symmetries of two gluon vacua.