An absence of neutrinos associated with cosmic-ray acceleration in γ-ray bursts

Journal article

Very energetic astrophysical events are required to accelerate cosmic rays to above 10¹⁸ electronvolts. GRBs (γ-ray bursts) have been proposed as possible candidate sources^1,2,3. In the GRB ‘fireball’ model, cosmic-ray acceleration should be accompanied by neutrinos produced in the decay of charged pions created in interactions between the high-energy cosmic-ray protons and γ-rays⁴. Previous searches for such neutrinos found none, but the constraints were weak because the sensitivity was at best approximately equal to the predicted flux^5,6,7. Here we report an upper limit on the flux of energetic neutrinos associated with GRBs that is at least a factor of 3.7 below the predictions^4,8,9,10. This implies either that GRBs are not the only sources of cosmic rays with energies exceeding 10¹⁸ electronvolts or that the efficiency of neutrino production is much lower than has been predicted.

Authors: Abbasi, R; Abdou, Y; Abu-Zayyad, T; Ackermann, M; Adams, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Nature
• Journal: Nature
• Volume: 484
• Issue: 7394
• Pages: 351-354
• Publication date: 2012-04-18
• Acceptance date: 2012-03-08
• DOI: 10.1038/nature11068
• EISSN: 1476-4687
• ISSN: 0028-0836
• Keywords: SBTMR; Astronomy and astrophysics