학술논문
Unusual Near-horizon Cosmic-ray-like Events Observed by ANITA-IV
Document Type
Working Paper
Author
ANITA Collaboration; Gorham, P. W.; Ludwig, A.; Deaconu, C.; Cao, P.; Allison, P.; Banerjee, O.; Batten, L.; Bhattacharya, D.; Beatty, J. J.; Belov, K.; Binns, W. R.; Bugaev, V.; Chen, C. H.; Chen, P.; Chen, Y.; Clem, J. M.; Cremonesi, L.; Dailey, B.; Dowkontt, P. F.; Fox, B. D.; Gordon, J. W. H.; Hast, C.; Hill, B.; Hsu, S. Y.; Huang, J. J.; Hughes, K.; Hupe, R.; Israel, M. H.; Liu, T. C.; Macchiarulo, L.; Matsuno, S.; McBride, K.; Miki, C.; Nam, J.; Naudet, C. J.; Nichol, R. J.; Novikov, A.; Oberla, E.; Olmedo, M.; Prechelt, R.; Prohira, S.; Rauch, B. F.; Roberts, J. M.; Romero-Wolf, A.; Rotter, B.; Russell, J. W.; Saltzberg, D.; Seckel, D.; Schoorlemmer, H.; Shiao, J.; Stafford, S.; Stockham, J.; Stockham, M.; Strutt, B.; Sutherland, M. S.; Varner, G. S.; Vieregg, A. G.; Wang, S. H.; Wissel, S. A.
Source
Phys. Rev. Lett. 126, 071103 (2021)
Subject
Language
Abstract
ANITA's fourth long-duration balloon flight in late 2016 detected 29 cosmic-ray (CR)-like events on a background of $0.37^{+0.27}_{-0.17}$ anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a characteristic phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous non-inverted polarity, a $p = 5.3 \times 10^{-4}$ chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply-upcoming anomalous events similar to the two such events seen in prior flights.
Comment: 6 pages, 4 figures, to appear in Physical Review Letters. Supplemental material (reference 17) available from corresponding author
Comment: 6 pages, 4 figures, to appear in Physical Review Letters. Supplemental material (reference 17) available from corresponding author