QCD thermodynamics with colour-sextet quarks

Abstract

We study QCD with two flavours of colour-sextet quarks as a candidate walking-Technicolor theory. We simulate lattice QCD with two flavours of colour-sextet staggered quarks at finite temperatures to observe the scales of confinement and chiral-symmetry breaking. These should give us some indication as to whether the massless theory has an infrared fixed point making it a conformal field theory, or whether it exhibits confinement and chiral symmetry breaking with a slowly varying coupling constant, i.e. `walks'. We find that unlike the case with fundamental quarks, the deconfinement and chiral-symmetry restoration transitions are far apart. The values of $\beta =6/g^2$ for both transitions increase when $Ta$ is decreased from 1/4 to 1/6 as would be expected for finite temperature transitions of an asymptotically-free field theory. So far we see no suggestion of conformal behaviour.

7 pages, 5 figures. Talk presented at Lattice 2009, Beijing, China. An expanded version was presented at XQCD 2009, Seoul, South Korea. New version with revised references. Minimal modification to text to accommodate revised references

References in corpus (7)

• Zero of the discrete beta function in SU(3) lattice gauge theory with color sextet fermions
• The physics of eight flavours
• Nearly conformal gauge theories in finite volume
• Conformal vs confining scenario in SU(2) with adjoint fermions
• Phase structure of SU(3) gauge theory with two flavors of symmetric-representation fermions
• Conformality or confinement: (IR)relevance of topological excitations
• The Conformal Window from the Worldline Formalism

Cited by in corpus (9)

• Unnatural Origin of Fermion Masses for Technicolor
• Thermodynamics of Quasi Conformal Theories From Gauge/Gravity Duality
• Higher Representations Duals
• Thermodynamics of a field theory with infrared fixed point from gauge/gravity duality
• Metastable nonconfining states in SU(3) lattice gauge theory with sextet fermions
• Chiral symmetry breaking in nearly conformal gauge theories
• The running coupling of the minimal sextet composite Higgs model
• Calculating the running coupling in strong electroweak models
• Spectrum of orientifold QCD in the strong coupling and hopping expansion approximation