Search for oscillations of a long-lived muon neutrino beam: a status report

A study of the time evolution of a long-lived ν/sub mu/ beam is being performed at Brookhaven National Laboratory (Experiment 704). The proton momentum (1.5 GeV/c2) is chosen to concentrate the ν/sub mu/ flux at very low energy where all background reactions are kinematically suppressed. Sensitivity to oscillations at large proper times tau varies as l/p (where l is the flight length and p is the momentum of the neutrino) is greatly enhanced by the resulting low neutrino momentum. Transformations ν/sub mu/ → ν/sub e/ are sensed via ν/sub e/n → e-p. An early exploratory test using the neutrino detector of the BNL elastic neutrino-proton scattering experiment will be run during 1977. A 200 ton detector for a definitive experiment is also discussed. 14 references