The decays ${\rho }^{-}\to \eta {\pi }^{-}$ and ${\tau }^{-}\to \eta ({\eta }^{\prime }){\pi }^{-}\nu$ in the NJL model

Abstract

The widths of the decays ${\rho }^{-}\to \eta {\pi }^{-}$ and ${\tau }^{-}\to \eta ({\eta }^{\prime }){\pi }^{-}\nu$ are calculated in the framework of the NJL model. It is shown that these decays are defined by the $u$ and $d$ quark mass difference. It leads to the suppression of these decays in comparison with the main decay modes. In the process ${\rho }^{-}\to \eta {\pi }^{-}$ the intermediate scalar $a_0^{-}$ state is taken into account. For the $\tau$ decays the intermediate states with $a_0^{-}$, ${\rho }^{-}(770)$ and ${\rho }^{-}(1450)$ mesons are used. Our estimates are compared with the results obtained in other works.

Comments: 6 pages, 5 figures, 1 table