QCD sum rules and chiral symmetry breaking
Journal
Z. Phys.
Journal Volume
C75
Pages
701-707
Date Issued
1996-01
Author(s)
Abstract
We investigate, in the context of QCD sum rules, the role of Goldstone bosons arising from chiral symmetry breaking, especially on the need of matching the world of hadrons to that of some effective chiral quark theory. We describe how such matching yields predictions on induced condensates which reproduce the observed value of the strong πNN coupling constant. Our result indicate that the observed large πNN coupling comes primarily from the nonperturbative induced-condensate effect. On the other hand, the prediction on the parity-violating weak πNN coupling, fπNN ∼ (3.0±0.5) × 10-7 is in good agreement with the value (∼ 2 × 10-7) obtained by Adelberger and Haxton from an overall fit to the existing data, but may appear to be slightly too large (but not yet of statistical significance) as compared to the most recent null experiment. Altogether, we wish to argue that the proposal of matching onto a chirally broken effective theory should enable us to treat, in a quantitative and consistent manner, the various nonleptonic strong and weak processes involving Goldstone bosons. © Springer-Verlag 1997.
Type
journal article