Different Faces of Confinement

Abstract

In this review, we provide a short outlook of some of the current most popular pictures and promising approaches to non-perturbative physics and confinement in gauge theories. A qualitative and by no means exhaustive discussion presented here covers such key topics as the phases of QCD matter, the order parameters for confinement, the central vortex and monopole pictures of the QCD vacuum structure, fundamental properties of the string tension, confinement realisations in gauge-Higgs and Yang–Mills theories, magnetic order/disorder phase transition, among others.

Neural network approach to reconstructing spectral functions and complex poles of confined particles

“…11, 14 and 15. Unlike the artificial test set, all reconstructions satisfied the first and the third constraint, while only 5% and 31% satisfied the second constraint for the 64 4 and 80 4 configuration respectively. As for the functions shown in Fig.…”

Probing confinement in a $\mathbb{Z}_2$ lattice gauge theory on a quantum computer

“…i , corresponding to a lattice version of Gauss's law. Such local gauge symmetries lead to a wide range of fundamental phenomena in LGTs, such as the masslessness of the photon in QED or the confinement of quarks in quantum chromodynamics [3,4]. Conserving these local symmetries for all simulated times t is the central challenge of gauge-theory quantum simulation.…”

“…A particularly rewarding target is given by lattice gauge theories (LGTs) [1,2]. Their constituents, e.g., charged matter and the electric gauge field, are governed by local gauge constraints, which are highly challenging to engineer and which lead to intriguing yet not fully understood features such as confinement of particles [3,4]. Here, we simulate confinement dynamics in a Z 2 LGT on a superconducting quantum chip.…”

“…Among the most fascinating phenomena in LGTs is confinement, by which the system dynamics is restricted due to interactions that are mediated via the gauge field. Confinement can give rise to bound meson excitations and in some cases is even associated with topological phases with non-Abelian anyons and charge fractionalization [4]. In the presence of both dynamical matter and gauge fields, the confinement problem is not fully understood, due to the difficulty of solving general LGTs using classical methods [3,8].…”

Cosmology from Strong Interactions

“…While being successful in interpretation of short-distance phenomena (i.e. in the weakly-coupled regime), a long-standing theoretical problem of dynamical description of the color confinement phenomenon in the infrared (or strongly-coupled) regime of QCD still remains the major unsolved problem of Standard Model (SM) of particle physics [21,22].…”