2025/05/10 by Tsutsui, Shoichiro, Asano, Yuhma, Ito, Yuta +5 · 2 citations
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Theory (hep-th) #Nuclear Theory (nucl-th) #Statistical Mechanics (cond-mat.stat-mech)
paper · doi:10.48550/arxiv.2505.06551
In our previous paper [JHEP 10 (2020) 144], we found that the complex Langevin (CL) method works for QCD at finite density on the 163 × 32 lattice in the low-temperature high-density regime within the range μ/ T = 1.6 - 9.6 with μ and T being the quark chemical potential and the temperature, which enabled us to see a clear trend towards the formation of the Fermi sphere. Here we investigate the validity of the CL method on the 243 × 12 lattice in the deconfined phase near the deconfinement phase transition. As before, we use four-flavor staggered fermions and judge the validity using the criterion based on the probability distribution of the drift term. The spatial extent is L = (1.3 - 2.7 \rm ~fm )> Λ\rm LQCD-1 ∼ 1\rm ~fm, in contrast to our previous study with L < Λ\rm LQCD-1. We find that the CL method works in a broad region up to μ/ T = 4.8, while it starts to fail as we approach the phase boundary due to the singular drift problem, which can be understood qualitatively by extending the Banks-Casher relation to the case at finite density.