Study of an anomalous tau lepton decay using a chiral Lagrangian with vector mesons

Abstract

The hadronic tau decay ${\tau }^{-}\to {\nu }_{\tau }\eta {\pi }^{-}{\pi }^0$ occurs through V-A weak current. In this decay mode, the vector current contribution is intrinsic parity violating and the axial current contribution is G parity violating. The latter contribution is suppressed due to tiny isospin breaking. We have computed both vector and axial vector form factors using a chiral Lagrangian with vector mesons including the effect of isospin breaking and intrinsic parity violation. A numerical result of the invariant mass distribution is shown and the structure of $\rho$ resonance can be seen in the distribution with respect to $M_{{\pi }^{-}{\pi }^0}$.

Comments: Talk presented at The 13 th International Workshop on Tau Lepton Physics (Aachen). 9 pages, 2 figures. In version 3, the erratum for reference [5] is added