Radiative decays of radially excited pseudoscalar mesons in the extended Nambu--Jona-Lasinio model

Abstract

In the extended NJL model the radiative decay widths of the radially excited states of the pseudoscalar $\pi$, $\eta$, and $\eta'$ mesons are calculated. The predictions for the decay widths of the processes $\pi(1300)\longrightarrow(\rho^0,\omega)\gamma$, $\eta(1295)\longrightarrow(\rho^0,\omega,\phi)\gamma$, and $\eta(1475)\longrightarrow(\rho^0,\omega,\phi)\gamma$ 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.