Processes ofe+e−→[η,η′,η(1295),η(1405)]γin the extended Nambu–Jona-Lasinio model

Abstract

In the extended Nambu--Jona-Lasinio (NJL) model the total cross sections of the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}[\ensuremath{\eta},{\ensuremath{\eta}}^{\ensuremath{'}},\ensuremath{\eta}(1295),\ensuremath{\eta}(1405)]\ensuremath{\gamma}$ at energies up to 2 GeV are calculated. The intermediate vector mesons $\ensuremath{\rho}(770)$, $\ensuremath{\omega}(782)$, $\ensuremath{\phi}(1020)$, ${\ensuremath{\rho}}^{\ensuremath{'}}(1450)$, ${\ensuremath{\omega}}^{\ensuremath{'}}(1420),$ and ${\ensuremath{\phi}}^{\ensuremath{'}}(1680)$ are taken into account. The latter three mesons are treated as the first radial excited states. They are incorporated into the NJL model by means of polynomial form factors. The calculation results are in satisfactory agreement with the experimental data obtained with the SND detector at VEPP-2M, Novosibirsk. The predictions given for the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}[{\ensuremath{\eta}}^{\ensuremath{'}},\ensuremath{\eta}(1295),\ensuremath{\eta}(1405)]\ensuremath{\gamma}$ have not been experimentally tested yet.