Unusually penetrating particle detected by balloon-borne emulsion chamber

M. Ichimura, Eiji Kamioka, M. Kitazawa, T. Kobayashi, T. Shibata, S. Somemiya, M. Kogawa, S. Kuramata, H. Matsutani, T. Murabayashi, H. Nanjyo, Z. Watanabe, H. Sugimoto, K. Nakazawa

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55 Citations (Scopus)

Abstract

One example of an unusual particle track has been recorded in an emulsion chamber exposed to cosmic rays on a ballon at the atmospheric depth 11.7 g/cm2. The particle arrived at the chamber with Z/β=40±2 and β≳0.8. What is extraordinary with this particle is its arrival zenith angle, 87.4°, which amounts to a traversed atmospheric thickness ∼200 g/cm2. The anomalous nature of the present track "ET" (exotic track) is demonstrated through the difficulties in reconciling it with the explanation that it is due to an ordinary ultra-heavy cosmic-ray nucleus.

Original languageEnglish
Pages (from-to)843-852
Number of pages10
JournalIl Nuovo Cimento A
Volume106
Issue number6
DOIs
Publication statusPublished - 1993 Jun
Externally publishedYes

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Keywords

  • Cosmic rays
  • Other and hypothetical particles (including tachyons)

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Nuclear and High Energy Physics
  • Astronomy and Astrophysics

Cite this

Ichimura, M., Kamioka, E., Kitazawa, M., Kobayashi, T., Shibata, T., Somemiya, S., ... Nakazawa, K. (1993). Unusually penetrating particle detected by balloon-borne emulsion chamber. Il Nuovo Cimento A, 106(6), 843-852. https://doi.org/10.1007/BF02771498