Polarization effects in tau production by neutrino

We studied polarization effects in tau production by neutrino-nucleon scattering. Quasi-elastic scattering, Δ resonance production and deep inelastic scattering processes are taken into account for the CERN-to-Gran Sasso projects. We show that the tau produced by neutrino has high degree of polarization, and its spin direction depends non-trivially on the energy and the scattering angle of tau in the laboratory frame.