Calculating the equation of state of dense quark-gluon plasma using the complex Langevin equation

摘要

The pressure and energy density of the quark-gluon plasma at finite baryon chemical potential are calculated using the complex Langevin equation. The stout smearing procedure is generalized for the SL(3, C) manifold allowing the usage of an improved action in the complex Langevin setup. Four degenerate flavors of staggered quarks with m_π = 500–700 MeV are used with a tree-level Symanzik improved gauge action on 16~3 × 8 lattices. Results are compared to the Taylor expansion and good agreement is found for small chemical potentials.