It has been hypothesized that large fluxes of neutrinos may be created in astrophysical 'cosmic accelerators.' The primary background for a search for astrophysical neutrinos comes from atmospheric ...neutrinos, which do not exhibit the pointlike directional clustering that characterizes a distant astrophysical signal. We perform a search for neutrino point sources using the upward-going muon data from three phases of operation (SK-I, SK-II, and SK-III) spanning 2623 days of live time taken from 1996 April 1 to 2007 August 11. The search looks for signals from suspected galactic and extragalactic sources, transient sources, and uncataloged sources. While we find interesting signatures from two objects-RX J1713.7-3946 (97.5% CL) and GRB 991004D (95.3% CL)-these signatures lack compelling statistical significance given trial factors. We set limits on the flux and fluence of neutrino point sources above energies of 1.6 GeV.
A search for a nonzero neutrino magnetic moment has been conducted using 1496 live days of solar neutrino data from Super-Kamiokande-I. Specifically, we searched for distortions to the energy ...spectrum of recoil electrons arising from magnetic scattering due to a nonzero neutrino magnetic moment. In the absence of a clear signal, we found micro(nu)</=(3.6x10(-10))micro(B) at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The fitting took into account the effect of neutrino oscillation on the shapes of energy spectra. With additional information from other solar neutrino and KamLAND experiments constraining the oscillation region, a limit of micro(nu)</=(1.1x10(-10))micro(B) at 90% C.L. was obtained.
A burst of eight neutrino events a preceding the optical detection of the supernova in the Large Magellanic Cloud has been observed in a large underground water Cherenkov detector. The events span an ...interval of 6 s and have visible energies in the range 20-40 MeV.
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