Abstract
We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of and , respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current () or charged-current () interactions within the IceCube detector. The events were discovered in a search for ultrahigh energy neutrinos using data corresponding to 615.9 days effective live time. The expected number of atmospheric background is . The probability of observing two or more candidate events under the atmospheric background-only hypothesis is () taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux; the moderate significance, however, does not permit a definitive conclusion at this time.
- Received 19 April 2013
DOI:https://doi.org/10.1103/PhysRevLett.111.021103
© 2013 American Physical Society
Synopsis
Energetic Neutrinos on Ice
Published 8 July 2013
The IceCube detector at the South Pole has observed two of the highest energy neutrinos ever recorded.
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