Probing lepton flavour violation in ν_(μ) + N to τ + ... scattering and μ to tau conversion on nucleons

We study lepton flavour-violating interactions which could result in the $\tau$-lepton production in the $\nu_{\mu}N$ scattering or in $\mu \to \tau$ conversion on nucleons at high energies. Phenomenological bounds on the strength of $\bar{\tau}\nu_{\mu}\bar{q}q^{'}$ interactions are extracted from the combined result of the NOMAD and CHORUS experiments on searching for $\nu_{\mu} - \nu_{\tau}$ oscillations. Some of these bounds supersede limits from rare decays. We also propose a ``missing energy'' type experiment searching for $\mu - \tau$ conversion on nucleons. The experiment can be performed at a present accelerator or at a future neutrino factory.