Constraints on Nucleon Decay via Invisible Modes from the Sudbury Neutrino Observatory

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to ``invisible'' modes, such as n→3ν. The analysis was based on a search for γ rays from the deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from ¹⁶O. A limit of τᵢₙᵥ>2×10²⁹ yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.