Abstract
We extend our previous formulation of low-energy QCD in terms of an effective lagrangean containing operators of dimensionality d ⩽ 6 constructed with pseudoscalars and quark fields, describing physics below the scale of chiral symmetry breaking. We include in this paper the vector and axial-vector channels. We follow closely the Extended Chiral Quark Model approach and consistently work in the large-Nc and leading log approximation and take into account the constraints from chiral symmetry and chiral symmetry restoration. The optimal fit of all parameters gives further support to a heavy scalar meson with a mass ∼ 1 GeV and a value of the axial pion-quark coupling constant gA ≃ 0.55 to 0.66, depending on some assumptions concerning the Weinberg sum rules.