The chiral phase transition and the axial anomaly

Abstract

To date numerical simulations of lattice QCD have not found a chiral phase transition of first order which is expected to occur for sufficiently light pions. We show how the restoration of an exact global chiral symmetry can strongly decrease the breaking of the approximate, anomalous $U_A(1)$ symmetry. This is testable on the lattice through simulations for one through four flavors. In QCD a small breaking of the $U_A(1)$ symmetry in the chirally symmetric phase generates novel experimental signals.

Updated discussion of literature

References in corpus (12)

• The order of the quantum chromodynamics transition predicted by the standard model of particle physics
• Bootstrapping phase transitions in QCD and frustrated spin systems
• Microscopic Origin of \boldmath{$U_A(1)$} Symmetry Violation in the High Temperature Phase of QCD
• On the strength of the $U_A(1)$ anomaly at the chiral phase transition in $N_f=2$ QCD
• QCD phase transitions in the light quark chiral limit
• One flavor QCD
• Topological susceptibility of pure gauge theory using Density of States
• U(2)xU(2)-symmetric fixed point from the Functional Renormalization Group
• Second order chiral phase transition in three flavor quantum chromodynamics?
• Fate of the ${\eta }^{\prime }$ in the Quark Gluon Plasma
• Anomalous interactions between mesons with nonzero spin and glueballs
• Berry's phase and chiral anomalies

Cited by in corpus (9)

• Anomalous $U(1{)}_A$ couplings and the Columbia plot
• Ordinary and exotic mesons in the extended Linear Sigma Model
• QCD topology and axion properties in an isotropic hot and dense medium
• $U_A(1)$ symmetry breaking quark interactions from vacuum polarization
• Range of topological fluctuations in the three-flavor linear sigma model
• Parity-doubled nucleons can rapidly cool neutron stars
• On the nature of the QCD chiral phase transition with imaginary chemical potential
• Different scenarios of dynamical chiral symmetry breaking in the interacting instanton liquid model via flavor symmetry breaking
• Studying the QCD phase diagram using pressure derivatives from lattice QCD