Extended Rein-Sehgal model for tau lepton production

The polarization density matrix formalism is employed to include the final lepton mass and spin into the popular model by Rein and Sehgal for single pion neutrinoproduction. We investigate the effect of the $\tau$ lepton mass on the differential cross sections. The lepton polarization evaluated within the extended RS model is compared against that follows from the single resonance production model based upon the Rarita-Schwinger formalism with phenomenological transition form factors.