First observation of PeV-energy neutrinos with IceCube

We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04±0.16 and 1.14±0.17  PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neut...

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Bibliographic Details
Main Authors: Aartsen, M., Abbasi, R., Abdou, Y., Ackermann, M., Adams, J., Aguilar, J., Ahlers, M., Altmann, D., Auffenberg, J., Bai, X., Baker, M., Barwick, S., Baum, V., Bay, R., Beatty, J., Bechet, S., Becker Tjus, J., Becker, K., Bell, M., Benabderrahmane, M., Benzvi, S., Berdermann, J., Berghaus, P., Berley, D., Bernardini, E., Bernhard, A., Bertrand, D., Besson, D., Binder, G., Bindig, D., Bissok, M., Blaufuss, E., Blumenthal, J., Boersma, D., Bohaichuk, S., Bohm, C., Bose, D., Böser, S., Botner, O., Brayeur, L., Bretz, H., Brown, A., Bruijn, R., Brunner, J., Carson, Michael, Casey, J., Casier, M., Chirkin, D., Christov, A., Christy, B., Clark, K., Clevermann, F., Coenders, S., Cohen, S., Cowen, D., Cruz Silva, A., Danninger, M., Daughhetee, J., Davis, J., De Clercq, C., De Ridder, S., Desiati, P., De With, M., Deyoung, T., Díaz-Vélez, J., Dunkman, M., Eagan, R., Eberhardt, B., Eisch, J., Ellsworth, R., Euler, S., Evenson, P., Fadiran, O., Fazely, A., Fedynitch, A., Feintzeig, J., Feusels, T., Filimonov, K., Finley, C., Fischer-Wasels, T., Flis, S., Franckowiak, A., Franke, R., Frantzen, K., Fuchs, T., Gaisser, T., Gallagher, J., Gerhardt, L., Gladstone, L., Glüsenkamp, T., Goldschmidt, A., Golup, G., Gonzalez, J., Goodman, J., Góra, D., Grant, D.
Format: Journal Article
Published: 2013
Online Access:http://hdl.handle.net/20.500.11937/41159
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Summary:We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04±0.16 and 1.14±0.17  PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current νe,μ,τ (ν¯e,μ,τ) or charged-current νe (ν¯e) 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 0.082±0.004(stat)+0.041−0.057(syst). The probability of observing two or more candidate events under the atmospheric background-only hypothesis is 2.9×10−3 (2.8σ) 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.