Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube


Abbasi R., Ackermann M., Adams J., Agarwalla S. K., Aguilar J. A., Ahlers M., ...More

PHYSICAL REVIEW LETTERS, vol.132, no.15, 2024 (SCI-Expanded) identifier identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 132 Issue: 15
  • Publication Date: 2024
  • Doi Number: 10.1103/physrevlett.132.151001
  • Journal Name: PHYSICAL REVIEW LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Compendex, INSPEC, zbMATH, DIALNET, Nature Index
  • Middle East Technical University Affiliated: No

Abstract

We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate v(tau) events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent v(tau) energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from pi(+/-)/K-+/- decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-v(tau) astrophysical neutrinos. Thus, we rule out the absence of astrophysical v(tau) at the 5 sigma level. The measured astrophysical v(tau) flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.