Dynamical chiral symmetry breaking and a critical mass
- Department of Physics, Peking University, Beijing 100871 (China)
On a bounded, measurable domain of non-negative current-quark mass, realistic models of the QCD gap equation can simultaneously admit two nonequivalent dynamical chiral symmetry breaking (DCSB) solutions and a solution that is unambiguously connected with the realization of chiral symmetry in the Wigner mode. The Wigner solution and one of the DCSB solutions are destabilized by a current-quark mass, and both disappear when that mass exceeds a critical value. This critical value also bounds the domain on which the surviving DCSB solution possesses a chiral expansion. This value can therefore be viewed as an upper bound on the domain within which a perturbative expansion in the current-quark mass around the chiral limit is uniformly valid for physical quantities. For a pseudoscalar meson constituted of equal-mass current quarks, it corresponds to a mass m{sub 0{sup -}} {approx} 0.45 GeV. In our discussion, we employ properties of the two DCSB solutions of the gap equation that enable a valid definition of <qq> in the presence of a nonzero current mass. The behavior of this condensate indicates that the essentially dynamical component of chiral symmetry breaking decreases with increasing current-quark mass.
- OSTI ID:
- 20990969
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 75, Issue 1; Other Information: DOI: 10.1103/PhysRevC.75.015201; (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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