skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Finite-size test for the finite-temperature chiral phase transition in lattice QCD

Abstract

A finite-size test was carried out for the finite-temperature chiral phase transition in QCD for flavor number {ital N}{sub {ital f}}=4 and 2 on a lattice with four time slices using the Kogut-Susskind quark action at quark mass of 0.025 in lattice units. All the evidence supports a first-order transition for {ital N}{sub {ital f}}=4. For {ital N}{sub {ital f}}=2, however, the data on spatial lattice up to 12{sup 3} fail to yield convincing finite-size signatures for a first-order transition at this quark mass.

Authors:
; ; ;  [1]
  1. (Research Institute for Fundamental Physics, Kyoto University, Kyoto (Japan) Faculty of Engineering, Yamanashi University, Kofu (Japan) National Laboratory for High Energy Physics (KEK), Ibaraki (Japan) Institute of Physics, University of Tsukuba, Ibaraki (Japan))
Publication Date:
OSTI Identifier:
6505774
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; (USA); Journal Volume: 65:7
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; LATTICE FIELD THEORY; PHASE TRANSFORMATIONS; QUANTUM CHROMODYNAMICS; CHIRAL SYMMETRY; MASS; NUMERICAL ANALYSIS; QUARKS; TEMPERATURE DEPENDENCE; ELEMENTARY PARTICLES; FERMIONS; FIELD THEORIES; MATHEMATICS; POSTULATED PARTICLES; QUANTUM FIELD THEORY; SYMMETRY; 645400* - High Energy Physics- Field Theory

Citation Formats

Fukugita, M., Mino, H., Okawa, M., and Ukawa, A. Finite-size test for the finite-temperature chiral phase transition in lattice QCD. United States: N. p., 1990. Web. doi:10.1103/PhysRevLett.65.816.
Fukugita, M., Mino, H., Okawa, M., & Ukawa, A. Finite-size test for the finite-temperature chiral phase transition in lattice QCD. United States. doi:10.1103/PhysRevLett.65.816.
Fukugita, M., Mino, H., Okawa, M., and Ukawa, A. 1990. "Finite-size test for the finite-temperature chiral phase transition in lattice QCD". United States. doi:10.1103/PhysRevLett.65.816.
@article{osti_6505774,
title = {Finite-size test for the finite-temperature chiral phase transition in lattice QCD},
author = {Fukugita, M. and Mino, H. and Okawa, M. and Ukawa, A.},
abstractNote = {A finite-size test was carried out for the finite-temperature chiral phase transition in QCD for flavor number {ital N}{sub {ital f}}=4 and 2 on a lattice with four time slices using the Kogut-Susskind quark action at quark mass of 0.025 in lattice units. All the evidence supports a first-order transition for {ital N}{sub {ital f}}=4. For {ital N}{sub {ital f}}=2, however, the data on spatial lattice up to 12{sup 3} fail to yield convincing finite-size signatures for a first-order transition at this quark mass.},
doi = {10.1103/PhysRevLett.65.816},
journal = {Physical Review Letters; (USA)},
number = ,
volume = 65:7,
place = {United States},
year = 1990,
month = 8
}
  • Lattice QCD with four flavors of light dynamical quarks is simulated on a 10/sup 3/ x 6 lattice in order to study the finite-temperature transition in the chiral limit. The mass used, m = 0.025 (in lattice units), is half the smallest value previously used on this size lattice. We find evidence for a finite-temperature phase transition which is absent for intermediate masses. The time evolution of the system shows both long correlation times characteristic of a nearby critical point and abrupt changes.
  • A previous finite-size study for the chiral phase transition of two-flavor QCD is extended to a smaller quark mass of {ital m}{sub {ital q}}=0.0125 in lattice units. The characteristics of the system for lattice sizes (6{sup 3}--12{sup 3}){times}4 are found to be quite similar to those for {ital m}{sub {ital q}}=0.025. The increase of susceptibilities over this range of the spatial size is still too mild to discriminate among the order of the transition also at this small quark mass.
  • We study the phase transition of the (3+1)-dimensional Yukawa model at finite temperature. We calculate the critical exponents in the 1/[ital N] expansion and clarify certain subtleties involved in such a calculation. In the leading order we do not find the presence of any of the metastable states which were claimed in the literature. To this order, the exponents are the mean field, but corrections shift them to the usual nontrivial values. Dimensional reduction of this model is studied with special attention paid to the discrete symmetries of the Lagrangian before and after reduction. In the reduced [ital d]=3 theorymore » there are two possible types of mass terms, one of which is allowed by chiral symmetry. It is the different discrete symmetries of these two mass terms which force the finite temperature 3 + 1 Yukawa Lagrangian to reduce to the usual scalar universality class (characterized by a conformally invariant [sigma] model) rather than the chiral universality class (characterized by [ital d]=3 conformally invariant NJL-type model).« less
  • We derive the linear Langevin equation to describe the dynamics of the chiral phase transition above the critical temperature by applying the projection operator method to the Nambu-Jona-Lasinio model at finite temperature and density. The relaxation time of the critical fluctuations increases as the temperature approaches toward the critical temperature because of the critical slowing down. The critical slowing down is enhanced in low temperature and large chemical potential region and around the tricritical point.
  • The Skyrme model, an effective low energy theory rooted in large N{sub c} QCD, has been applied to the study of dense matter. Matter is described by various crystal structures of Skyrmions. When this system is heated, the dominating thermal degrees of freedom are the fluctuating pions. Taking these mechanisms jointly produces a description of the chiral phase transition leading to the conventional phase diagram with critical temperatures and densities in agreement with expected values.