Conformality in many-flavour lattice QCD at strong coupling

Abstract

It is widely believed that chiral symmetry is spontaneously broken at zero temperature in the strong coupling limit of staggered fermions, for any number of colors and flavors. Using Monte Carlo simulations, we show that this conventional wisdom, based on a mean-field analysis, is wrong. For sufficiently many fundamental flavors, chiral symmetry is restored via a bulk, first-order transition. This chirally symmetric phase appears to be analytically connected with the expected conformal window of many-flavor continuum QCD. We perform simulations in the chirally symmetric phase at zero quark mass for various system sizes L, and measure the torelon mass, the Dirac spectrum and the hadron spectrum. All masses go to zero with 1/L. L is hence the only infrared length scale. Thus, the strong-coupling chirally restored phase appears as a convenient laboratory to study IR-conformality. Finally, we present a conjecture for the phase diagram of lattice QCD as a function of the bare coupling and the number of quark flavors.

15 pages, 12 figures. Notation clarified, discussion expanded, to appear in JHEP

References in corpus (3)

• A precise determination of the psibar-psi anomalous dimension in conformal gauge theories
• Jumping Dynamics
• Lattice QCD with 12 Degenerate Quark Flavors

Cited by in corpus (27)

• The lattice QCD phase diagram in and away from the strong coupling limit
• Scale-dependent mass anomalous dimension from Dirac eigenmodes
• 125 GeV Higgs from a not so light Technicolor Scalar
• On the particle spectrum and the conformal window
• The bulk transition of QCD with twelve flavors and the role of improvement
• Jumping Dynamics
• Global Structure of Conformal Theories in the SU(3) Gauge Theory
• The Yang-Mills gradient flow and SU(3) gauge theory with 12 massless fundamental fermions in a colour-twisted box
• Anomalous dimensions on the lattice
• Safety versus triviality on the lattice
• Lattice Monte-Carlo study of pre-conformal dynamics in strongly flavoured QCD in the light of the chiral phase transition at finite temperature
• One,Two,Zero: Scales of Strong Interactions
• Absence of chiral symmetry breaking in multi-flavor strongly coupled lattice gauge theories
• Large N lattice QCD and its extended strong-weak connection to the hypersphere
• Spectrum of SU(2) gauge theory at large number of flavors
• Chiral symmetry restoration at large chemical potential in strongly coupled SU(N) gauge theories
• Features of a 2d Gauge Theory with Vanishing Chiral Condensate
• QCD chiral symmetry restoration with a large number of quarks in a model with a confining propagator and dynamically massive gluons
• Baryon bags in strong coupling QCD
• Phase Structure Study of SU(2) Lattice Gauge Theory with 8 Flavors
• Chiral symmetry in $SU(N_c)$ gauge theories at high density
• QCD fixed points: Banks-Zaks scenario or dynamical gluon mass generation?
• Mass anomalous dimension of SU(2) with Nf=8 using the spectral density method
• Safe Hologram
• Calculating the chiral condensate diagrammatically at strong coupling
• IR-conformal gauge theories and composite Higgs
• Conformality at large number of fermion flavors and composite Higgs