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arXiv · hep-ph/9909366

The Extended Chiral Quark Model confronts QCD

A. A. Andrianov·D. Espriu·R. Tarrach
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Abstract

We discuss the truncation of low energy effective action of QCD below the chiral symmetry breaking (CSB) scale, including all operators of dimensionality less or equal to 6 which can be built with quark and chiral fields. We perform its bosonization in the scalar, pseudoscalar, vector and axial-vector channels in the large-N_c and leading-log approximation. Constraints on the coefficients of the effective lagrangian are derived from the requirement of Chiral Symmetry Restoration (CSR) at energies above the CSB scale in the scalar-pseudoscalar and vector-axial-vector channels, from matching to QCD at intermediate scales, and by fitting some hadronic observables. In this truncation two types of pseudoscalar states (massless pions and massive Pi'-mesons), as well as a scalar, vector and axial-vector one arise as a consequence of dynamical chiral symmetry breaking. Their masses and coupling constants as well as a number of chiral structural constants are derived. A reasonable fit of all parameters supports a relatively heavy scalar meson (quarkonium) with the mass \sim 1 GeV and a small value of axial pion-quark coupling constant g_A \simeq 0.55.

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A. A. Andrianov, D. Espriu, R. Tarrach. 1999-09-14. The Extended Chiral Quark Model confronts QCD. https://doi.org/10.1016/s0920-5632(00)00576-4

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