  The hadronic current for the $\tau^- \to \pi^-\pi^+\pi^-\nu_\tau$ decay
calculated in the framework of the Resonance Chiral Theory with an additional
modification to include the $\sigma$ meson is described. Implementation into
the Monte Carlo generator Tauola and fitting strategy to get the model
parameters using the one-dimensional distributions are discussed. The results
of the fit to one-dimensional mass invariant spectrum of the BaBar data are
presented.
