2024/04/24 by Rafael C. Torres, Torres, Rafael C., Nuno Cardoso +7
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Theory (hep-th) #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions #Strongly Correlated Electrons (cond-mat.str-el) #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.2404.15907
openalex publication_date 2024/04/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The 4D compact U(1) gauge theory has a well-established phase transition between a confining and a Coulomb phase. In this paper, we revisit this model using state-of-the-art Monte Carlo simulations on anisotropic lattices. We map out the coupling-temperature phase diagram, and determine the location of the tricritical point, T/K0 ≃ 0.19, below which the first-order transition is observed. We find the critical exponents of the high-temperature second-order transition to be compatible with those of the 3-dimensional O(2) model. Our results at higher temperatures can be compared with literature results and are consistent with them. Surprisingly, below T/K0 ≃ 0.05 we find strong indications of a second tricritical point where the first-order transition becomes continuous. These results suggest an unexpected second-order phase transition extending down to zero temperature, contrary to the prevailing consensus. If confirmed, these findings reopen the question of the detailed characterization of the transition including a suitable field theory description.