Scalar susceptibility from the instanton vacuum with meson-loop corrections
- Yukawa Institute for Theoretical Physics (YITP), Kyoto University, Kyoto 606-8502 (Japan)
The scalar susceptibility ({chi}{sub s}) of QCD, which represents the response of the chiral condensate to a small perturbation of explicit chiral-symmetry breaking (m{ne}0), is investigated within the nonlocal chiral quark model (NL{chi}QM) based on the instanton vacuum configuration for N{sub f}=2. We also take into account 1/N{sub c} meson-loop (ML) corrections including scalar and pseudoscalar mesons. It turns out that the chiral condensate is modified to a large extend by the ML corrections in the vicinity of m=0, whereas its effect becomes weak beyond m{approx_equal}100 MeV. As numerical results, we find that {chi}{sub s}=-0.34 GeV{sup 2} with the ML corrections and 0.18 GeV{sup 2} without it. From these observations, we conclude that the ML corrections play an important role in the presence of finite current-quark mass.
- OSTI ID:
- 21254691
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 79, Issue 1; Other Information: DOI: 10.1103/PhysRevD.79.014008; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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