Thermodynamics of lattice QCD with 2 sextet quarks on N{sub t}=8 lattices

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.074504· OSTI ID:21607799

Kogut, J B; Sinclair, D K ^[1]

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1. Department of Energy, Division of High Energy Physics, Washington, DC 20585 (United States) and Department of Physics-TQHN, University of Maryland, 82 Regents Drive, College Park, Maryland 20742 (United States)

We continue our lattice simulations of QCD with 2 flavors of color-sextet quarks as a model for conformal or walking technicolor. A 2-loop perturbative calculation of the {beta} function which describes the evolution of this theory's running coupling constant predicts that it has a second zero at a finite coupling. This nontrivial zero would be an infrared stable fixed point, in which case the theory with massless quarks would be a conformal field theory. However, if the interaction between quarks and antiquarks becomes strong enough that a chiral condensate forms before this IR fixed point is reached, the theory is QCD-like with spontaneously broken chiral symmetry and confinement. However, the presence of the nearby IR fixed point means that there is a range of couplings for which the running coupling evolves very slowly, i.e. it ''walks.'' We are simulating the lattice version of this theory with staggered quarks at finite temperature, studying the changes in couplings at the deconfinement and chiral-symmetry restoring transitions as the temporal extent (N{sub t}) of the lattice, measured in lattice units, is increased. Our earlier results on lattices with N{sub t}=4, 6 show both transitions move to weaker couplings as N{sub t} increases consistent with walking behavior. In this paper we extend these calculations to N{sub t}=8. Although both transitions again move to weaker couplings, the change in the coupling at the chiral transition from N{sub t}=6 to N{sub t}=8 is appreciably smaller than that from N{sub t}=4 to N{sub t}=6. This indicates that at N{sub t}=4, 6 we are seeing strong-coupling effects and that we will need results from N{sub t}>8 to determine if the chiral-transition coupling approaches zero as N{sub t}{yields}{infinity}, as needed for the theory to walk.

• OSTI ID: 21607799
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIMATTER
ANTIPARTICLES
ANTIQUARKS
CHIRAL SYMMETRY
CHIRALITY
COMPUTERIZED SIMULATION
CONDENSATES
CONFINEMENT
CONFORMAL INVARIANCE
CONSTRUCTIVE FIELD THEORY
COUPLING
COUPLING CONSTANTS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
INTERACTIONS
INVARIANCE PRINCIPLES
LATTICE FIELD THEORY
MATHEMATICAL MODELS
MATTER
PARTICLE MODELS
PARTICLE PROPERTIES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKS
SIMULATION
STRONG-COUPLING MODEL
SYMMETRY
THERMODYNAMICS