Three-meson $\tau$ decays involving kaons and $\eta$ mesons in the NJL model

Branching fractions of decays $\tau \to K^0 \pi^- \eta\nu_\tau$, $\tau \to K^- \pi^0 \eta\nu_\tau$, $\tau \to K^-K^0 \eta\nu_\tau$ and $\tau \to K^- \eta \eta \nu_\tau$ are calculated in the $U(3)\times U(3)$ chiral NJL quark model. The contact, vector, axial-vector and pseudoscalar channels are considered. It is shown that the axial vector channel is dominant. The obtained results are in satisfactory agreement with experiment.

M.K. Volkov, A.A. Pivovarov, K. Nurlan · 2023