Lattice pure gauge compact QED in the Landau gauge: The photon propagator, the phase structure, and the presence of Dirac strings

In this work we investigate the lattice Landau gauge photon propagator together with the average number of Dirac strings in the compact formulation of QED for the pure gauge version of the theory as a function of the coupling constant. Their beta dependence show that these two quantities can be used to identify the confinement-deconfinement transition and that the nature of this transition is first order. Our results show that in the confined phase the propagator is always finite, the theory has a mass gap and the number of Dirac strings present in a configuration is two orders of magnitude larger than in the deconfined phase. Furthermore, in the deconfined phase where beta >= 1.0125 the theory becomes massless, there are essentially no Dirac strings and the photon propagator diverges when the limit p -> 0(+) is taken. Our results illustrate the importance of the topological structures in the dynamics of the two phases.

Automated summary

By investigating the lattice Landau gauge photon propagator and the average number of Dirac strings, we found that they can be used to identify the confinement-deconfinement transition, which is of first order. In the confined phase, the propagator is finite with a mass gap, and the number of Dirac strings is two orders of magnitude larger compared to the deconfined phase. In the deconfined phase, the theory becomes massless with essentially no Dirac strings present.