Speaker
Hans Niederhausen
(Stony Brook Univ.)
Description
We have performed a new measurement of the all-sky diffuse flux of high energy, E>10TeV, extraterrestrial neutrino induced showers (cascades) based on IceCube data collected during 641 days in 2010--2012. Cascades arise predominantly in electron and tau neutrino interactions and have good energy resolution, so that they are well-suited for the spectral characterization of the extraterrestrial flux. For the first time, we have included also high-energy cascades with vertices in near proximity to the detector, thereby enlarging the event sample by up to a factor of two for E > 100TeV. A total of 172 cascades with energies ranging from 10TeV to 1PeV have been observed, of which approximately 60% (75% above 100TeV) have not previously been reported by IceCube. Based on Monte Carlo simulations we estimate the neutrino purity to be 95%. The dominant extra-terrestrial component is well described by a smooth and featureless power-law. The result is in agreement with previous IceCube results and is preferred over a background-only hypothesis with a significance of more than 4 sigma. Additionally we will present a comparison between the results obtained when upward oriented and downward oriented showers are considered separately, showing that the extraterrestrial neutrino fluxes originating from the Northern and Southern hemispheres are consistent.
| Registration number following "ICRC2015-I/" | 938 |
|---|---|
| Collaboration | IceCube |
Primary authors
Mr
Achim Stoessl
(DESY Zeuthen)
Hans Niederhausen
(Stony Brook Univ.)
Dr
Mariola Lesiak-Bzdak
(Stony Brook University)
