Constraining tau-sterile neutrino mixing with high-energy astrophysical neutrinos
Abstract
Whether a sterile neutrino mixes with the three active ones remains an open question. Its mixing with the tau neutrino, |Uτ4|2, is the least constrained, since terrestrial experiments probe it only indirectly and over limited ranges of sterile-neutrino mass. We show that TeV-PeV astrophysical neutrinos probe it differently. Their sources make almost no ντ, but oscillations over cosmological distances turn about one third of them into ντ before they reach Earth. Mixing with a sterile neutrino would make these ντ scarcer, lowering the ντ fraction that neutrino telescopes measure, whatever the sterile-neutrino mass. In contrast, sterile mixing with νe or νμ is nearly undetectable. Fitting the flavor composition measured by IceCube, with the composition at the sources left free, we find |Uτ4|2 < 0.88 at 90% C.L. Combining IceCube with present and planned neutrino telescopes, including IceCube-Gen2 and HUNT, could lower this limit to 0.24-0.29 by 2040 and to 0.12-0.14 by 2050. By 2050, these limits would match some present terrestrial limits, though not the strongest.
Related
- Sensitivities of long and medium baseline experiments to sterile neutrinos and non-standard interactions
- Probing eV-scale sterile neutrinos with neutrinoless double-beta decay and beta decay
- Sensitivities of Long and Medium Baseline Experiments to Sterile Neutrinos and Non-Standard Interactions
- Axion-like particles and sterile neutrinos solve the B→ Kνν̅ and B→ πK puzzles
- IceCube data for astrophysical neutrinos exhibit q-statistical behavior
BibTeX
@misc{bustamante2026constraining,
title = {{Constraining tau-sterile neutrino mixing with high-energy astrophysical neutrinos}},
author = {Mauricio Bustamante and Qinrui Liu},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.05170},
eprint = {2611.05170},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.05170},
}
RIS
TY - UNPB
TI - Constraining tau-sterile neutrino mixing with high-energy astrophysical neutrinos
AU - Mauricio Bustamante
AU - Qinrui Liu
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.05170
UR - https://arxiv.org/abs/2611.05170
AB - Whether a sterile neutrino mixes with the three active ones remains an open question. Its mixing with the tau neutrino, |U_τ4|^2, is the least constrained, since terrestrial experiments probe it only indirectly and over limited ranges of sterile-neutrino mass. We show that TeV-PeV astrophysical neutrinos probe it differently. Their sources make almost no ν_τ, but oscillations over cosmological distances turn about one third of them into ν_τ before they reach Earth. Mixing with a sterile neutrino would make these ν_τ scarcer, lowering the ν_τ fraction that neutrino telescopes measure, whatever the sterile-neutrino mass. In contrast, sterile mixing with ν_e or ν_μ is nearly undetectable. Fitting the flavor composition measured by IceCube, with the composition at the sources left free, we find |U_τ4|^2 < 0.88 at 90% C.L. Combining IceCube with present and planned neutrino telescopes, including IceCube-Gen2 and HUNT, could lower this limit to 0.24-0.29 by 2040 and to 0.12-0.14 by 2050. By 2050, these limits would match some present terrestrial limits, though not the strongest.
ER -