Neutrino oscillation searches at CERN

Various neutrino oscillation projects which have been put forth at CERN are discussed. Three proposals use the present detectors: BEBC, CDHS, and CHARM. They require a new low-energy neutrino beam, which is being constructed. One proposal uses the present high-energy SPS beam. It requires a new fine-grain detector. Approval of this experiment is still pending. There are two methods of measuring oscillations. The disappearance method measures the flux of a given neutrino (in our case nu/sub μ/ as a function of the distance R from the production target. Without oscillation the flux decreases as 1/R2; with oscillation it decreases faster. In the appearance method a new species of neutrino is searched for, for instance nu/sub e/ in a pure nu/sub μ/ initial beam. For experimental reasons, CDHS and CHARM use the disappearance method between two detectors positioned at two different distances, while BEBC chooses the appearance method, at a fixed distance. The high-energy experiment proposes to use the two methods simultaneously, thus having extra control over possible sources if an effect is found