Lattice Landau gauge photon propagator for 4D compact QED

In this work we report on the Landau gauge photon propagator computed for pure gauge 4D compact QED in the confined and deconfined phases and for large lattice volumes: 32(4), 48(4) and 96(4). In the confined phase, compact QED develops mass scales that render the propagator finite at all momentum scales and no volume dependence is observed for the simulations performed. Furthermore, for the confined phase the propagator is compatible with a Yukawa massive type functional form. For the deconfined phase the photon propagator seems to approach a free field propagator as the lattice volume is increased. In both cases, we also investigate the static potential and the average value of the number of Dirac strings in the gauge configurations m. In the confined phase the mass gap translates into a linearly growing static potential, while in the deconfined phase the static potential approaches a constant at large separations. Results shows that m is, at least, one order of magnitude larger in the confined phase and confirm that the appearance of a confined phase is connected with the topology of the gauge group.

Automated summary

In this study, the Landau gauge photon propagator for pure gauge 4D compact QED in confined and deconfined phases was computed for different lattice volumes. The results show that in the confined phase, the propagator is finite at all momentum scales, while in the deconfined phase it approaches a free field propagator as the lattice volume increases. The static potential and average number of Dirac strings in gauge configurations exhibit distinct behaviors in the two phases, with the mass gap in the confined phase leading to a linearly growing static potential.