Thermodynamics of lattice QCD with 2 flavors of color-sextet quarks: A model of walking/conformal technicolor

Journal Article · Tue Jun 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.114507· OSTI ID:21407991

Kogut, J B; Sinclair, D K ^[1]

---

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

QCD with two flavors of massless color-sextet quarks is considered as a model for conformal/walking technicolor. If this theory possesses an infrared fixed point, as indicated by 2-loop perturbation theory, it is a conformal (unparticle) field theory. If, on the other hand, a chiral condensate forms on the weak-coupling side of this would-be fixed point, the theory remains confining. The only difference between such a theory and regular QCD is that there is a range of momentum scales over which the coupling constant runs very slowly (walks). In this first analysis, we simulate the lattice version of QCD with two flavors of staggered quarks at finite temperatures on lattices of temporal extent N{sub t}=4 and 6. The deconfinement and chiral-symmetry restoration couplings give us a measure of the scales associated with confinement and chiral-symmetry breaking. We find that, in contrast to what is seen with fundamental quarks, these transition couplings are very different. {beta}=6/g{sup 2} for each of these transitions increases significantly from N{sub t}=4 and N{sub t}=6 as expected for the finite-temperature transitions of an asymptotically free theory. This suggests a walking rather than a conformal behavior, in contrast to what is observed with Wilson quarks. In contrast to what is found for fundamental quarks, the deconfined phase exhibits states in which the Polyakov loop is oriented in the directions of all three cube roots of unity. At very weak coupling the states with complex Polyakov loops undergo a transition to a state with a real, negative Polyakov loop.

• OSTI ID: 21407991
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 11; Other Information: DOI: 10.1103/PhysRevD.81.114507; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
CHIRALITY
COUPLING
COUPLING CONSTANTS
FIELD THEORIES
PERTURBATION THEORY
QUANTUM CHROMODYNAMICS
QUARKS
SYMMETRY BREAKING
THERMODYNAMICS
TRANSITION TEMPERATURE
WILSON LOOP
FERMIONS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
QUANTUM FIELD THEORY
SYMMETRY
THERMODYNAMIC PROPERTIES