Abstract
We discuss the influence of closed Dirac strings on the photon propagator in the Landau gauge emerging from a study of the compact gauge model in dimensions. This gauge also minimizes the total length of the Dirac strings. Closed Dirac strings are stable against local gauge-fixing algorithms only due to the torus boundary conditions of the lattice. We demonstrate that these leftover Dirac strings are responsible for the previously observed unphysical behavior of the propagator of spacelike photons in the deconfinement (high temperature) phase. We show how one can monitor the number of thermal Dirac strings which allows us to separate the propagator measurements into sectors. The propagator in sectors is characterized by a nonzero mass and an anomalous dimension similarly to the confinement phase. Both the mass squared and anomalous dimension are found to be proportional to Consequently, in the sector the unphysical behavior of the photon propagator is cured and the deviation from the free massless propagator disappears.
- Received 21 November 2003
DOI:https://doi.org/10.1103/PhysRevD.69.094502
©2004 American Physical Society