New Neutrino Detection Technology: Application of Massive Water Detectors to Accelerator Neutrino Physics

Abstract

In surveying the field of new detector technology, it appears that the advent of massive, inexpensive water Cerenkov detectors may have a significant impact on future neutrino physics. These detectors offer the volumes necessary to perform experiments at very low fluxes, for example with long neutrino flight paths or with rare neutrino species (e. g. ν_e). As an illustration of the potential on the new techniques, we consider in detail an experiment dedicated to the study of the time evolution of a neutrino beam enriched with ν_e’s. The highest fluxes of ν_e appear to be achieved with current beam lines at the Brookhaven AGS or the CERN PS. An array of massive, inexpensive detectors allows a configuration optimized for good sensitivity to neutrino eigenmass differences from 0.6 eV to 20 eV and mixing angles down to 15° (comparable to the Cabibbo angle). The ν_e beam is formed using

$$\mathop {\text{K}}\nolimits_{{\text{e3}}}^{\text{o}}$$

decays. A simultaneously produced ν_μ beam from

$$\mathop {\text{K}}\nolimits_{{\text{e3}}}^{\text{o}}$$

decay serves as the normalizer. Pion generated ν_μ’s are suppressed to limit background. The detector consists of a series of seven water Cerenkov modules (each with 175T fiducial mass), judiciously spaced along the ν line to provide flight paths from 40m to 1000m. Simulation and reconstruction of neutrino events in a detector similar to the one considered show sufficient resolution in angle, energy, position and event timing relative to the beam.