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The Beamforming Elevated Array for COsmic Neutrinos (BEACON) is a concept for a neutrino telescope designed to detect radio emission from upgoing air showers induced by tau leptons that are generated by ultra-high energy tau neutrino interactions in the Earth. This detection mechanism provides a pure measurement of the tau flavor of cosmogenic and astrophysical neutrinos, which could be used to set limits on the observed flavor ratios in a manner complimentary to the all-flavor neutrino flux measurements made by other experiments. A BEACON prototype has been installed at high elevation at Barcroft Field Station for several years and consists of 4 crossed-dipole antennas operating in the 30-80 MHz band and connected to a custom DAQ. The BEACON prototype is at high elevation to maximize effective volume and uses a directional beamforming trigger to reduce man-made background signals at the trigger level. This prototype system is expected to be capable of detecting downgoing cosmic ray air showers, a signal like the upgoing tau lepton air shower, but distinguishable chiefly by arrival direction. Here we give an overview of the BEACON experiment and present an ongoing cosmic ray search with data from the BEACON prototype. Cosmic ray candidates that are identified by this search will be used to experimentally determine the sensitivity of the BEACON concept to the known cosmic ray flux, which can then be used to predict the sensitivity of a full-scale BEACON array to the cosmogenic and astrophysical neutrino fluxes.
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Detection of astrophysical tau neutrino candidates in IceCube
Abstract High-energy tau neutrinos are rarely produced in atmospheric cosmic-ray showers or at cosmic particle accelerators, but are expected to emerge during neutrino propagation over cosmic distances due to flavor mixing. When high energy tau neutrinos interact inside the IceCube detector, two spatially separated energy depositions may be resolved, the first from the charged current interaction and the second from the tau lepton decay. We report a novel analysis of 7.5 years of IceCube data that identifies two candidate tau neutrinos among the 60 “High-Energy Starting Events” (HESE) collected during that period. The HESE sample offers high purity, all-sky sensitivity, and distinct observational signatures for each neutrino flavor, enabling a new measurement of the flavor composition. The measured astrophysical neutrino flavor composition is consistent with expectations, and an astrophysical tau neutrino flux is indicated at 2.8 $$\sigma $$ σ significance.
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- PAR ID:
- 10425957
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Date Published:
- Journal Name:
- The European Physical Journal C
- Volume:
- 82
- Issue:
- 11
- ISSN:
- 1434-6052
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1140/epjc/s10052-022-10795-y
