First-order Chiral Phase Transition Research Articles

Metastabilities in three-flavor QCD at low quark masses.

Using a Langevin algorithm to incorporate low-mass dynamical quarks, we simulate QCD with three light flavors on an ${8}^{3}$\ifmmode\times\else\texttimes\fi{}4 lattice. We find clear metastabilities in lattice measurables at a quark mass of 0.025 in lattice units, whereas earlier analyses at 4 times the mass above did not prove their presence. Our results suggest a first-order chiral phase transition in three-flavor QCD. We also confirm the presence of a stronger first-order transition with four flavors and indicate the possibility of a weaker first-order transition with two flavors.

Numerical evidence for a first-order chiral phase transition in lattice QCD with two light flavors.

Finite-temperature behavior of quantum chromodynamics with two light dynamical flavors is studied by Langevin simulation on a ${8}^{3}$\ifmmode\times\else\texttimes\fi{}4 lattice with the Kogut-Susskind quark action. It is found that the chiral transition strengthens as the quark mass ${m}_{q}$ decreases towards zero, changing from a continuous crossover at ${m}_{q}$a=0.2 to a first-order transition at ${m}_{q}$a=0.1. The critical coupling at ${m}_{q}$=0 is estimated to be ${\ensuremath{\beta}}_{c}$=6/${g}_{c}^{2}$=5.29--5.32, and the physical scale of ${T}_{c}$\ensuremath{\simeq}(0.19--0.24)${m}_{\ensuremath{\rho}}$. .AE

First-order chiral phase transition in lattice QCD

The chiral phase transition in lattice QCD has been studied for light fermions of mass ma=0.025 on lattices of size 4 4 and 8 3×4 using the hybrid algorithm. We find evidence for a first-order chiral phase transition with a large latent heat. A comparison with 10 3×6 data shows violations of asymptotic scaling for T ch which are similar in magnitude to those observed in the pure gauge sector.