Characterization of the astrophysical diffuse neutrino flux using starting track events in IceCube
Abstract
A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interaction. Searching for these starting track events allows us to not only more effectively reject atmospheric muons but also atmospheric neutrino backgrounds in the southern sky, opening a new window to the sub-100 TeV astrophysical neutrino sky. The event selection is constructed using a dynamic starting track veto and machine learning algorithms. We use this data to measure the astrophysical diffuse flux as a single power law flux (SPL) with a best-fit spectral index of γ =2.5 8-0.09+0.10 and per-flavor normalization of ϕper-flavor Astro=1.6 8-0.22+0.19×10-18×GeV-1 cm-2 s-1 sr-1 (at 100 TeV). The sensitive energy range for this dataset is 3-550 TeV under the SPL assumption. This data was also used to measure the flux under a broken power law, however we did not find any evidence of a low energy cutoff.
- Publication:
-
Physical Review D
- Pub Date:
- July 2024
- DOI:
- 10.1103/PhysRevD.110.022001
- arXiv:
- arXiv:2402.18026
- Bibcode:
- 2024PhRvD.110b2001A
- Keywords:
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- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 27 pages, 28 figures