Dual superconductivity and vacuum properties in Yang–Mills theories

Abstract

We address, within the dual superconductivity model for color confinement, the question whether the Yang-Mills vacuum behaves as a superconductor of type I or type II. In order to do that we compare, for the theory with gauge group SU (2), the determination of the field penetration depth λ with that of the superconductor correlation length ξ. The latter is obtained by measuring the temporal correlator of a disorder parameter developed by the Pisa group to detect dual superconductivity. The comparison places the vacuum close to the border between type I and type II and marginally on the type II side. We also check our results against the study of directly measurable effects such as the interaction between two parallel flux tubes, obtaining consistent indications for a weak repulsive behaviour. Future strategies to improve our investigation are discussed.

QCD flux tubes across the deconfinement phase transition

“…Indeed, Monte Carlo simulations produce samples of vacuum configurations that, in principle, contain all the relevant information on the nonperturbative sector of QCD. A wealth of numerical analyses in QCD has firmly established that the chromoelectric field between a static quark-antiquark pair distributes in tubelike structures or "flux tubes" [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. From these tubelike structures a linear potential between static color charges naturally arises, thus representing a numerical evidence of color confinement.…”

Chromoelectric flux tubes in QCD

“…In particular, Monte Carlo simulations can produce samples of vacuum configurations that can be used to get insight into the non-perturbative sector of QCD. Tube-like structures emerge by analyzing the chromoelectric field between static quarks [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]. Such tube-like structures naturally lead to linear potential and consequently to a "phenomenological" understanding of color confinement.…”

Superconductivity in Restricted Chromo-Dynamics (RCD) in SU(2) and SU(3) Gauge Theories

“…This idea of Abelian dominance has recently been verified by gauge fixing and Abelian projection [35] and also by constructing semilocal models in Extended Abelian Higgs model (EAH-model) [36,37]. The same idea has been used, more recently, in connection with the dual Meissner effect in local unitary gauges in SU(2) gluo-dynamics [38] and also with confining ensemble of dyons [39] and dual superconductivity in Yang-Mills theories [40].…”