Observation of an Unusual Upward-going Cosmic-ray-like Event in the Third Flight of ANITA

P. W. Gorham; B. Rotter; P. Allison; O. Banerjee; L. Batten; J. J. Beatty; K. Bechtol; K. Belov; D. Z. Besson; W. R. Binns; V. Bugaev; P. Cao; C. C. Chen; C. H. Chen; P. Chen; J. M. Clem; A. Connolly; L. Cremonesi; B. Dailey; C. Deaconu; P. F. Dowkontt; B. D. Fox; J. W. H. Gordon; C. Hast; B. Hill; K. Hughes; J. J. Huang; R. Hupe; M. H. Israel; A. Javaid; J. Lam; K. M. Liewer; S. Y. Lin; T. C. Liu; A. Ludwig; L. Macchiarulo; S. Matsuno; C. Miki; K. Mulrey; J. Nam; C. J. Naudet; R. J. Nichol; A. Novikov; E. Oberla; M. Olmedo; R. Prechelt; S. Prohira; B. F. Rauch; J. M. Roberts; A. Romero-Wolf; J. W. Russell; D. Saltzberg; D. Seckel; H. Schoorlemmer; J. Shiao; S. Stafford; J. Stockham; M. Stockham; B. Strutt; G. S. Varner; A. G. Vieregg; S. H. Wang; S. A. Wissel

doi:10.1103/physrevlett.121.161102

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arXiv · 1803.05088

Observation of an Unusual Upward-going Cosmic-ray-like Event in the Third Flight of ANITA

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Abstract

We report on an upward traveling, radio-detected cosmic-ray-like impulsive event with characteristics closely matching an extensive air shower. This event, observed in the third flight of the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload, is consistent with a similar event reported in a previous flight. These events may be produced by the atmospheric decay of an upward-propagating $\tau$-lepton produced by a $\nu_{\tau}$ interaction, although their relatively steep arrival angles create tension with the standard model (SM) neutrino cross section. Each of the two events have $a~posteriori$ background estimates of $\lesssim 10^{-2}$ events. If these are generated by $\tau$-lepton decay, then either the charged-current $\nu_{\tau}$ cross section is suppressed at EeV energies, or the events arise at moments when the peak flux of a transient neutrino source was much larger than the typical expected cosmogenic background neutrinos.

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P. W. Gorham, B. Rotter, P. Allison, O. Banerjee, L. Batten, J. J. Beatty, K. Bechtol, K. Belov, D. Z. Besson, W. R. Binns, V. Bugaev, P. Cao, C. C. Chen, C. H. Chen, P. Chen, J. M. Clem, A. Connolly, L. Cremonesi, B. Dailey, C. Deaconu, P. F. Dowkontt, B. D. Fox, J. W. H. Gordon, C. Hast, B. Hill, K. Hughes, J. J. Huang, R. Hupe, M. H. Israel, A. Javaid, J. Lam, K. M. Liewer, S. Y. Lin, T. C. Liu, A. Ludwig, L. Macchiarulo, S. Matsuno, C. Miki, K. Mulrey, J. Nam, C. J. Naudet, R. J. Nichol, A. Novikov, E. Oberla, M. Olmedo, R. Prechelt, S. Prohira, B. F. Rauch, J. M. Roberts, A. Romero-Wolf, J. W. Russell, D. Saltzberg, D. Seckel, H. Schoorlemmer, J. Shiao, S. Stafford, J. Stockham, M. Stockham, B. Strutt, G. S. Varner, A. G. Vieregg, S. H. Wang, S. A. Wissel. 2018-03-14. Observation of an Unusual Upward-going Cosmic-ray-like Event in the Third Flight of ANITA. https://doi.org/10.1103/physrevlett.121.161102

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