Abstract We discuss the role of the U(1) axial symmetry for the phase structure of QCD at finite temperature. We expect that, above a certain critical temperature, also the U(1) axial symmetry will be (effectively) restored. We will try to see if this transition has (or has not) anything to do with the usual chiral transition: various possible scenarios are discussed. In particular, supported by recent lattice results, we analyze a scenario in which a U(1)-breaking condensate survives across the chiral transition. This scenario can be consistently reproduced using an effective Lagrangian model. The effects of the U(1) chiral condensate on the slope of the topological susceptibility in the full theory with quarks are studied: we find that this quantity (in the chiral limit of zero quark masses) acts as an order parameter for the U(1) axial symmetry above the chiral transition. Further information on the new U(1) chiral order parameter is derived from the study (at zero temperature) of the radiative decays of the “light” pseudoscalar mesons in two photons: a comparison of our results with the experimental data is performed.
Reviewing the problem of the U(1) axial symmetry and the chiral transition in QCD
Published 2003 in Nuclear Physics
ABSTRACT
PUBLICATION RECORD
- Publication year
2003
- Venue
Nuclear Physics
- Publication date
2003-01-28
- Fields of study
Physics
- Identifiers
- External record
- Source metadata
Semantic Scholar
CITATION MAP
EXTRACTION MAP
CLAIMS
- No claims are published for this paper.
CONCEPTS
- No concepts are published for this paper.
REFERENCES
Showing 1-44 of 44 references · Page 1 of 1
CITED BY
Showing 1-13 of 13 citing papers · Page 1 of 1