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Title: Results from the High Resolution Fly's Eye Experiment

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.3628706· OSTI ID:21608333
 [1]
  1. Department of Physics, University of Utah, 115 S. 1400 E. Rm. 201 Salt Lake City, Utah, 84112-0830 (United States)

The High Resolution Fly's Eye (HiRes) Experiment operated two fluorescence detector sites in the western Utah desert between 1997 and 2006. The HiRes results on the cosmic ray spectrum are consistent with the GZK Suppression predicted at 10{sup 19.8} eV and observe an ankle structure at 10{sup 18.5} eV. These spectral features are consistent with a proton-dominated composition for cosmic rays at the highest energies. The HiRes composition studies of both the mean and the variance of the shower maximum depth (X{sub max}) also give results that are completely consistent with a predominately protonic composition, and inconsistent with heavy nuclei such as iron. We also report on the result of anisotropy studies.

OSTI ID:
21608333
Journal Information:
AIP Conference Proceedings, Vol. 1367, Issue 1; Conference: International symposium on the recent progress of ultra-high energy cosmic ray observation, Aichi (Japan), 10-12 Dec 2010; Other Information: DOI: 10.1063/1.3628706; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English