arXiv subjects
Publications and source records attributed to A. V. Vishneva.
The width of the decay $τ\rightarrow f_1 πν_τ$ has recently been measured by the BaBar experiment. The estimation of this width is given in the framework of the NJL model with the axial-vector mesons. Prediction is in agreement with the experimental data. It is shown that the $π-a_1$ transition contribution plays an important role and allows us to bring the NJL prediction to the data.
The first radial excitations of axial-vector mesons are considered in the framework of the extended $U(3)\times U(3)$ Nambu--Jona-Lasinio model. We calculate the mass spectrum of $a_1$, $f_1$, and also strange axial-vector mesons. For description of radially excited states we used the form factors of polynomial type of the second order in transverse quark momentum. For the ground- and the excited-state mesons consisting of light quarks we have calculated the widths of a number of strong and radiative decays. We got satisfactory agreement with experimental data for the ground states. A set of predictions for the excited states of mesons is given.
In the extended NJL model the radiative decay widths of the radially excited states of the pseudoscalar $π$, $η$, and $η'$ mesons are calculated. The predictions for the decay widths of the processes $π(1300)\longrightarrow(ρ^0,ω)γ$, $η(1295)\longrightarrow(ρ^0,ω,ϕ)γ$, and $η(1475)\longrightarrow(ρ^0,ω,ϕ)γ$ are given. Nowadays, there are no solid experimental data for these processes. The comparison of the results obtained in the framework of the standard and the extended NJL models for decays of the ground states of mesons is given. It is shown that these calculations correspond to each other and are also in satisfactory agreement with experimental data. This allows one to expect that the extended NJL can give reliable predictions for the excited states of mesons.