Contained neutrino interactions in an underground water detector

Abstract

We study 401 neutrino interactions which have been collected in a massive, well-shielded underground detector. The sample is used to test for neutrino oscillations with a sensitivity in Δ$m^2$≥4.2×${10}^{\mathrm{-}5}$ ${\mathrm{eV}}^2$ at maximum mixing (90% confidence level). A search is made for terrestrial and extraterrestrial point sources of neutrinos. A limit on point sources in the energy range 500–2000 MeV is given. A search is made for possible evidence for geomagnetic effects on the data. Most of the neutrinos are likely of atmospheric origin.