First search for atmospheric and extraterrestrial neutrino-induced cascades with the IceCube detector

Journal article

We report on the first search for atmospheric and for diffuse astrophysical neutrino-induced showers (cascades) in the IceCube detector using 257 days of data collected in the year 2007-2008 with 22 strings active. A total of 14 events with energies above 16TeV remained after event selections in the diffuse analysis, with an expected total background contribution of 8.3±3.6. At 90% confidence we set an upper limit of E2Φ90%CL<3. 6×10-7GeV•cm-2•s-1•sr -1 on the diffuse flux of neutrinos of all flavors in the energy range between 24TeV and 6.6PeV assuming that ΦE-2 and the flavor composition of the νeνμντ flux is 111 at the Earth. The atmospheric neutrino analysis was optimized for lower energies. A total of 12 events were observed with energies above 5TeV. The observed number of events is consistent with the expected background, within the uncertainties. © 2011 American Physical Society.

Authors: Abbasi, R; Abdou, Y; Abu-Zayyad, T; Adams, J; Aguilar, J

• Journal: Physical Review D
• Volume: 84
• Issue: 7
• Publication date: 2011-10-03
• DOI: 10.1103/PhysRevD.84.072001
• EISSN: 1550-2368
• ISSN: 1550-7998
• Language: English