Evidence for a conformal phase in SU(N) gauge theories

Abstract

We discuss the existence of a conformal phase in SU(N) gauge theories in four dimensions. In this lattice study we explore the model in the bare parameter space, varying the lattice coupling and bare mass. Simulations are carried out with three colors and twelve flavors of dynamical staggered fermions in the fundamental representation. The analysis of the chiral order parameter and the mass spectrum of the theory indicates the restoration of chiral symmetry at zero temperature and the presence of a Coulomb-like phase, depicting a scenario compatible with the existence of an infrared stable fixed point at nonzero coupling. Our analysis supports the conclusion that the onset of the conformal window for QCD-like theories is smaller than Nf=12, before the loss of asymptotic freedom at sixteen and a half flavors. We discuss open questions and future directions.

11 pages, 11 figures; extended analysis, conclusions unchanged. (version to appear in PRD)

References in corpus (7)

• Conformality Lost
• On the magnetic equation of state in (2+1)-flavor QCD
• Chiral phase boundary of QCD at finite temperature
• The physics of eight flavours
• Conformal vs confining scenario in SU(2) with adjoint fermions
• Conformal Windows of SU(N) Gauge Theories, Higher Dimensional Representations and The Size of The Unparticle World
• Comments on lattice gauge theories with infrared-attractive fixed points

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