First Double Cascade Tau Neutrino Candidates in IceCube and a New Measurement of the Flavor Composition
The IceCube Neutrino Observatory at the South Pole, which detects Cherenkov light from charged particles produced in neutrino interactions, firmly established the existence of an astrophysical high-energy neutrino component. The expected neutrino flavor composition on Earth is $ν_e:ν_μ:ν_τ$ of about...
| Main Author: | |
|---|---|
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
arXiv
2019
|
| Subjects: | |
| Online Access: | https://dx.doi.org/10.48550/arxiv.1908.05506 https://arxiv.org/abs/1908.05506 |
| Summary: | The IceCube Neutrino Observatory at the South Pole, which detects Cherenkov light from charged particles produced in neutrino interactions, firmly established the existence of an astrophysical high-energy neutrino component. The expected neutrino flavor composition on Earth is $ν_e:ν_μ:ν_τ$ of about 1:1:1 for neutrinos produced in astrophysical sources through pion decay. A measurement of the flavor composition on Earth can provide important constraints on sources and production mechanisms within the standard model, and can also constrain various beyond-standard-model processes. Here the measurement of the flavor composition performed on IceCube's High-Energy Starting Events sample with a livetime of about 7.5 years is presented. IceCube is directly sensitive to each neutrino flavor via the single cascade, track and double cascade event topologies. In IceCube, $ν_τ$-CC interactions above $\sim$ 100 TeV can produce resolvable double cascades, breaking the degeneracy between $ν_e$ and $ν_τ$ present at lower energies. IceCube's first two identified double cascades are presented and the properties of the two $ν_τ$ candidates are discussed. : Presented at the 36th International Cosmic Ray Conference (ICRC 2019). See arXiv:1907.11699 for all IceCube contributions |
|---|