Tau polarization in neutrino-nucleon quasi-elastic and Δ resonance production

The effect of Fermi motion in the spin polarization of τ± leptons produced in quasi-elastic ντ and ντ¯ nucleon scattering and Δ resonance production is discussed. The τ polarization can play role in measurement of the τ appearance rate in neutrino oscillation experiments due to the fact, that decay particle distributions depend on τ± spin.