Characteristics of Four Upward-Pointing Cosmic-Ray-like Events Observed with ANITA

P W Gorham; J Nam; A Romero-Wolf; S Hoover; P Allison; O Banerjee; J J Beatty; K Belov; D Z Besson; W R Binns; V Bugaev; P Cao; C Chen; P Chen; J M Clem; A Connolly; B Dailey; C Deaconu; L Cremonesi; P F Dowkontt; M A DuVernois; R C Field; B D Fox; D Goldstein; J Gordon; C Hast; C L Hebert; B Hill; K Hughes; R Hupe; M H Israel; A Javaid; J Kowalski; J Lam; J G Learned; K M Liewer; T C Liu; J T Link; E Lusczek; S Matsuno; B C Mercurio; C Miki; P Miočinović; M Mottram; K Mulrey; C J Naudet; J Ng; R J Nichol; K Palladino; B F Rauch; K Reil; J Roberts; M Rosen; B Rotter; J Russell; L Ruckman; D Saltzberg; D Seckel; H Schoorlemmer; S Stafford; J Stockham; M Stockham; B Strutt; K Tatem; G S Varner; A G Vieregg; D Walz; S A Wissel; F Wu; ANITA Collaboration

doi:10.1103/PhysRevLett.117.071101

Characteristics of Four Upward-Pointing Cosmic-Ray-like Events Observed with ANITA

Phys Rev Lett. 2016 Aug 12;117(7):071101. doi: 10.1103/PhysRevLett.117.071101. Epub 2016 Aug 8.

Authors

P W Gorham¹, J Nam², A Romero-Wolf³, S Hoover⁴, P Allison^{5

6}, O Banerjee⁵, J J Beatty^{5

6}, K Belov³, D Z Besson⁷, W R Binns⁸, V Bugaev⁸, P Cao⁹, C Chen², P Chen², J M Clem⁹, A Connolly^{5

6}, B Dailey⁵, C Deaconu¹⁰, L Cremonesi¹¹, P F Dowkontt⁴, M A DuVernois¹, R C Field¹², B D Fox¹, D Goldstein¹³, J Gordon⁵, C Hast¹², C L Hebert¹, B Hill¹, K Hughes⁵, R Hupe⁵, M H Israel⁸, A Javaid⁹, J Kowalski¹, J Lam⁴, J G Learned¹, K M Liewer³, T C Liu², J T Link¹, E Lusczek¹⁴, S Matsuno¹, B C Mercurio⁵, C Miki¹, P Miočinović¹, M Mottram¹¹, K Mulrey⁹, C J Naudet³, J Ng¹², R J Nichol¹¹, K Palladino⁵, B F Rauch⁸, K Reil¹², J Roberts¹, M Rosen¹, B Rotter¹, J Russell¹, L Ruckman¹, D Saltzberg⁴, D Seckel⁹, H Schoorlemmer¹, S Stafford⁵, J Stockham⁷, M Stockham⁷, B Strutt¹¹, K Tatem¹, G S Varner¹, A G Vieregg¹⁰, D Walz¹², S A Wissel¹⁵, F Wu⁴; ANITA Collaboration

Affiliations

¹ Department of Physics and Astronomy, University of Hawaii, Manoa, Hawaii 96822, USA.
² Department of Physics, Graduate Institute of Astrophysics and Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan.
³ Jet Propulsion Laboratory, Pasadena, California 91109, USA.
⁴ Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095, USA.
⁵ Department of Physics, Ohio State University, Columbus, Ohio 43210, USA.
⁶ Center for Cosmology and Particle Astrophysics, Ohio State University, Columbus, Ohio 43210, USA.
⁷ Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA.
⁸ Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130, USA.
⁹ Department of Physics, University of Delaware, Newark, Delaware 19716, USA.
¹⁰ Department of Physics, Enrico Fermi Institute, Kavli Institute for Cosmological Physics, University of Chicago, Chicago, Illinois 60637, USA.
¹¹ Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom.
¹² SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
¹³ Department of Physics, University of California, Irvine, California 92697, USA.
¹⁴ School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
¹⁵ Physics Department, California Polytechnic State University, San Luis Obispo, California 93407, USA.

PMID: 27563945
DOI: 10.1103/PhysRevLett.117.071101

Abstract

We report on four radio-detected cosmic-ray (CR) or CR-like events observed with the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload. Two of the four were previously identified as stratospheric CR air showers during the ANITA-I flight. A third stratospheric CR was detected during the ANITA-II flight. Here, we report on characteristics of these three unusual CR events, which develop nearly horizontally, 20-30 km above the surface of Earth. In addition, we report on a fourth steeply upward-pointing ANITA-I CR-like radio event which has characteristics consistent with a primary that emerged from the surface of the ice. This suggests a possible τ-lepton decay as the origin of this event, but such an interpretation would require significant suppression of the standard model τ-neutrino cross section.