Description of the decay $\tau \to K\pi \pi {\nu }_{\tau }$ in the NJL type chiral quark model

The branching fractions of the decays ${\tau }^{-}\to K^{-}{\pi }^{+}{\pi }^{-}{\nu }_{\tau }$, ${\tau }^{-}\to K^{-}{\pi }^0{\pi }^0{\nu }_{\tau }$ and ${\tau }^{-}\to {\bar{K}}^0{\pi }^{-}{\pi }^0{\nu }_{\tau }$ are calculated in the $U(3)\times U(3)$ Nambu–Jona-Lasinio type chiral model. Four intermediate channels are considered: the contact channel and the channels with the intermediate axial vector, vector and pseudoscalar mesons. The additional resonance states $K^{\ast }\pi$ and $K\rho$ are taken into account in all channels. It is shown that the main contributions to the widths of these decays are given by the axial vector channel. In the axial vector channel, the intermediate resonances $K_1(1270)$ and $K_1(1400)$ are taken into account. The obtained results are in satisfactory agreement with the known experimental data.