  The recently discovered high-energy transient Swift J164449.3+573451 (Sw
J1644+57) is thought to arise from the tidal disruption of a passing star by a
dormant massive black hole. Modeling of the broadband emission suggests the
presence of a powerful relativistic jet, which contributes dominantly to the
observed X-ray emission. Here we suggest that protons can be accelerated to
ultra-high energies by internal shocks occurring in the jets, but their flux is
insufficient to account for the observed flux of ultra-high energy cosmic rays.
High energy protons can produce ~0.1-10 PeV neutrinos through photomeson
interactions with X-ray photons. The large X-ray fluence (7x10^-4 erg cm^-2)
and high photopion efficiency, together with the insignificant cooling of
secondary mesons, result in bright neutrino emission expected from Sw J1644+57
if the jet composition is matter-dominated. One to several neutrinos may be
detected by a Km^3-scale detector from one tidal disruption event similar to Sw
J1644+57, thereby providing a powerful probe of the composition of the jets.
