No abstract

A chiral SU (2) × SU (2) Lagrangian containing, besides the usual meson fields, their first radial excitations is considered. The Lagrangian is derived by bosonization of the NambuJona-Lasinio quark model with separable non-local interactions, with form factors corresponding to 3-dimensional ground and excited state wave functions. The spontaneous breaking of chiral symmetry is governed by the NJL gap equation. The first radial excitations of the pions, ρ-and ω-mesons are described with the help of two form factors. The weak decay constant F π ′ is calculated. The values for the decay widths of the processes ρ → 2π, π ′ → ρπ, ρ ′ → 2π, ρ ′ → ωπ and ω ′ → ρπ are obtained in agreement with the experimental data.

In the analysis a status and parameters of the scalar, vector, and tensor mesonic resonances are obtained and compared with other results. Possible classification of the resonance states in terms of the SU(3) multiplets is discussed.

The chiral perturbation theory is developed at the quark level within the extended Nambu-Jona-Lasinio model, which we used for the low-energy approximation of QCD in the leading order of the large N expansion. In terms of constituent-quark loop diagrams we analyze all of the main low-energy effects caused by the first order corrections in the current-quark-mass expansions. For the correct description of the η→3π decays we confirm the important role of the final-state interaction quoted by Gasser and Leutwyler.