Flavor symmetry breaking and meson masses
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843 (United States)
- Department of Physics, Peking University, Beijing 100871 (China)
- Center for Nuclear Research, Department of Physics, Kent State University, Kent, Ohio 44242 (United States)
The axial-vector Ward-Takahashi identity is used to derive mass formulas for neutral pseudoscalar mesons. Flavor symmetry breaking entails nonideal flavor content for these states. Adding that the {eta}{sup '} is not a Goldstone mode, exact chiral-limit relations are developed from the identity. They connect the dressed-quark propagator to the topological susceptibility. It is confirmed that in the chiral limit the {eta}{sup '} mass is proportional to the matrix element which connects this state to the vacuum via the topological susceptibility. The implications of the mass formulas are illustrated using an elementary dynamical model, which includes an Ansatz for that part of the Bethe-Salpeter kernel related to the non-Abelian anomaly. In addition to the current-quark masses, the model involves two parameters, one of which is a mass-scale. It is employed in an analysis of pseudoscalar- and vector-meson bound-states. While the effects of SU(N{sub f}=2) and SU(N{sub f}=3) flavor symmetry breaking are emphasized, the five-flavor spectra are described. Despite its simplicity, the model is elucidative and phenomenologically efficacious; e.g., it predicts {eta}-{eta}{sup '} mixing angles of {approx}-15 deg. and {pi}{sup 0}-{eta} angles of {approx}1 deg.
- OSTI ID:
- 21067838
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 76, Issue 4; Other Information: DOI: 10.1103/PhysRevC.76.045203; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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