Center Vortices and Ghosts

TL;DR

This paper investigates the role of center vortices in confinement by analyzing their impact on the ghost form factor in different gauges, supported by lattice calculations, revealing a link between vortices and infrared divergence.

Contribution

It demonstrates that center vortices cause infrared divergence in the ghost form factor in certain gauges, and this divergence disappears when vortices are removed, highlighting their role in confinement.

Findings

Infrared divergence occurs in gauges sensitive to vortices.

Removing vortices eliminates the divergence.

Lattice calculations support the theoretical analysis.

Abstract

Assuming that center vortices are the confining gauge field configurations, we argue that in gauges that are sensitive to the confining center vortex degrees of freedom, and where the latter lie on the Gribov horizon, the corresponding ghost form factor is infrared divergent. Furthermore, this infrared divergence disappears when center vortices are removed from the Yang-Mills ensemble. On the other hand, for gauge conditions which are insensitive to center vortex degrees of freedom, the ghost form factor is infrared finite and does not change (qualitatively) when center vortices are removed. Evidence for our observation is provided from lattice calculations.