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The Nambu–Jona-Lasinio model is applied to describe processes of electron-positron annihilation into mesons at center-of-mass energies below 2GeV and hadronic decays of tau leptons. Contributions of intermediate scalar, vector, and axial-vector mesons in the ground and first radial excited states are taken into account. Comparisons with existing experimental data are performed. Theoretical predictions for several(not yet measured)processes are presented.

In the extended U (3) × U (3) NJL quark model, semileptonic decays of ρ , ω , ϕ , η and η ′ mesons in both the ground and first radially excited states are described. Quark loops of the anomalous type are considered, which are based on the vertex η → V V . The obtained results are in satisfactory agreement with the existing experimental data. In addition, a number of predictions for experimentally unmeasured decays of radially excited mesons are presented. [ABSTRACT FROM AUTHOR]

The branching fractions of the decays τ → a 1 π ν τ , τ → K 1 π ν τ and τ → K 1 K ν τ are calculated in the framework of the extended U (3) × U (3) chiral Nambu–Jona-Lasinio model. There are no experimental data for these decays in the present time, thus the obtained results are considered as predictions. The comparison of these results to the theoretical results of other authors is carried out. [ABSTRACT FROM AUTHOR]

The U (3) × U (3) chiral symmetric NJL model describing pseudoscalar, vector, and axial-vector mesons in both the ground state and first radially excited states is shortly presented in this review. In this model, it is possible to describe a large number of low-energy interactions of mesons, τ lepton decays into mesons, and processes of meson production in electron–positron annihilations in satisfactory agreement with the experiments. In describing a number of processes, it turned out to be necessary to take into account the interactions of mesons in the final state. [ABSTRACT FROM AUTHOR]