Remarks on the U(1) axial symmetry and the chiral transition in QCD at finite temperature

Abstract

We discuss the role of the U(1) axial symmetry for the scalar and pseudoscalar meson mass spectrum of QCD at finite temperature, above the chiral transition at T_c, using a chiral effective Lagrangian model, which, in addition to the usual chiral condensate, also includes a (possible) genuine U(1)_A-breaking condensate that (possibly) survives across the chiral transition. The motivations for considering this Lagrangian (and a critical comparison with other effective Lagrangian models existing in the literature) are presented. A detailed comparison between the case N_f=3 (or N_f>3) and the (remarkably different) case N_f=2 is performed. The results obtained in the case N_f=2 are also critically compared with the available lattice results.

arXiv commentRevised version, published in PRD; 28 pages, 1 table, 1 figure

References in corpus (22)

• The chiral and deconfinement aspects of the QCD transition
• Possibility of spontaneous parity violation in hot QCD
• Theta dependence of SU(N) gauge theories in the presence of a topological term
• Chiral Symmetry Restoration at Nonzero Temperature in the SU(3) \times SU(3) Linear Sigma Model
• Relevance of the axial anomaly at the finite-temperature chiral transition in QCD
• The QCD chiral transition, $\ua$ symmetry and the Dirac spectrum using domain wall fermions
• The chiral transition and U(1)_A symmetry restoration from lattice QCD using Domain Wall Fermions
• Chiral symmetry restoration, eigenvalue density of Dirac operator and axial U(1) anomaly at finite temperature
• Finite temperature study of the axial U(1) symmetry on the lattice with overlap fermion formulation
• Meson screening masses from lattice QCD with two light and the strange quark
• Chiral symmetry restoration in linear sigma models with different numbers of quark flavors
• Lattice QCD at Finite Temperature and Density
• On the nature of the finite-temperature transition in QCD
• Which Chiral Symmetry is Restored in High Temperature QCD?
• Anomalous Chiral Symmetry Breaking above the QCD Phase Transition
• Topology, fermionic zero modes and flavor singlet correlators in finite temperature QCD
• U(1) Axial Symmetry and Correlation Functions in the High Temperature Phase of QCD
• The finite temperature QCD phase transition with domain wall fermions
• Reviewing the problem of the U(1) axial symmetry and the chiral transition in QCD
• Thermodynamics for two flavor QCD
• $X$ Meson aka ${\eta }^{\prime }$ and Kobayashi-Maskawa-'t Hooft Six-quark Vertex -- $U(1{)}_A$ Anomaly and Generalized Nambu-Jona-Lasinio Model --
• The effects of an extra U(1) axial condensate on the radiative decay eta' --> gamma gamma at finite temperature

Cited by in corpus (15)

• The QCD chiral transition, $\ua$ symmetry and the Dirac spectrum using domain wall fermions
• Chiral and $U(1{)}_A$ restoration for the scalar/pseudoscalar meson nonets
• Patterns and partners for chiral symmetry restoration
• U(2)xU(2)-symmetric fixed point from the Functional Renormalization Group
• Pion and $\eta$-meson mass splitting at the two-flavour chiral crossover
• Exploring axial $U(1)$ restoration in a modified 2+1 flavor Polyakov quark meson model
• Study of the interactions of the axion with mesons and photons using a chiral effective Lagrangian model
• How tetraquarks can generate a second chiral phase transition
• Study of the theta dependence of the vacuum energy density in chiral effective Lagrangian models at zero temperature
• QCD axion and topological susceptibility in chiral effective Lagrangian models at finite temperature
• Light quarks at finite temperature: chiral restoration and the fate of the $U(1{)}_A$ symmetry
• The pion-kaon scattering amplitude and the $K^0(700)$ and $K^{\ast }(892)$ resonances at finite temperature
• The role of strangeness in chiral and $U(1{)}_A$ restoration
• Study of some local and global $U(1)$ axial condensates in QCD at finite temperature
• Theta dependence of the vacuum energy density in chiral effective Lagrangian models at finite temperature, above $T_c$