# Approximate UA(1) restoration at high temperatures and the spectrum of pseudoscalar mesons

TL;DR: In this article, the effect of symmetry restoration on pseudoscalar mass spectrum was studied and the possibility of U(3) becoming an exact symmetry at high temperatures was considered.

Abstract: The effect of UA(1) symmetry restoration on the pseudoscalar mass spectrum is studied. The possibility of U(3) becoming an exact symmetry at high temperatures is considered.

##### Citations

More filters

••

[...]

TL;DR: In this paper, a comprehensive analysis of the mass and mixing angel of η and η ′ reveals that in the transition of the quark-gluon-plasma droplets to the hadrons, besides the chiral phase transition, the U A (1) phase transition also plays a significant and non-trivial role.

Abstract: We study chiral and U A (1) phase transition in the dilute gas approximation. A comprehensive analysis of the mass and mixing angel of η and η ′ reveals that in the transition of the quark-gluon-plasma droplets to the hadrons, besides the chiral phase transition, the U A (1) phase transition also plays a significant and non-trivial role.

1 citations

##### References

More filters

••

[...]

TL;DR: In this paper, the phase transition restoring chiral symmetry at finite temperatures is considered in a linear σ-sigma model. But the model is not suitable for the case of massless flavors.

Abstract: The phase transition restoring chiral symmetry at finite temperatures is considered in a linear $\ensuremath{\sigma}$ model. For three or more massless flavors, the perturbative $\ensuremath{\epsilon}$ expansion predicts the phase transition is of first order. At high temperatures, the ${\mathrm{U}}_{A}(1)$ symmetry will also be effectively restored.

800 citations

••

[...]

TL;DR: In this article, a careful analysis of the Ward identities involving the axial divergences partial/sup..mu../A..mu.., combined with a fit to the 2..gamma.. decays of the..pi../sup 0/, eta, and eta' via the quantum electrodynamic anomaly, allows a consistent description of the pseudoscalar nonet with zero (or small) quantum chromodynamic surface term.

Abstract: A careful analysis of the Ward identities involving the axial divergences partial/sup ..mu../A..mu.., combined with a fit to the 2..gamma.. decays of the ..pi../sup 0/, eta, and eta' via the quantum electrodynamic anomaly, allows a consistent description of the pseudoscalar nonet with zero (or small) quantum chromodynamic surface term. The gluonic matrix elements of the eta and eta' obtained from the Ward identities lead to a good quantitative understanding of the relative rates (psi ..-->.. eta'..gamma..)/(psi ..-->.. eta..gamma..), and a qualitative understanding of the nonsuppression of psi' ..-->.. psieta.

42 citations

••

[...]

TL;DR: Anomalous Ward identities were obtained for spontaneously realized SU(3) x SU( 3) x U/sub 3/(1) in the presence of realistic symmetry-breaking quark mass terms in the Lagrangian.

Abstract: Anomalous Ward identities are obtained for spontaneously realized SU(3) x SU(3) x U/sub 3/(1) in the presence of realistic symmetry-breaking quark mass terms in the Lagrangian It is shown that the Ward identities contain more information than has hitherto been utilized Together with low-energy theorems for pi/sup 0/, eta, and eta'-->2gamma decays these provide a set of equations which are solved for the axial-vector couplings and topological-charge (or glueball) components of eta and eta'

11 citations

••

[...]

TL;DR: In this paper, the complete set of anomalous Ward identities for the spontaneous breaking of U(3) × U (3) applied to the pseudoscalar nonet spectrum is shown to provide evidence for gluons, gluon anomalies and non-trivial topological charge.

Abstract: The complete set of anomalous Ward identities for the spontaneous breaking of U(3) × U(3) applied to the pseudoscalar nonet spectrum is shown to provide evidence for gluons, gluon anomalies and non-trivial topological charge. Solutions of the Ward identities give estimates both of the average topological charge of QCD and the underlying pure Yang-Mills theory of gluons. The application of one of the Ward identities ignored in previous phenomenological analyses leads to a clearer understanding of the decays ψ→ηγ and η'γ, and explains the enhancement of SU(3) breaking effects in these decays.

9 citations