First Observation of the Greisen-Zatsepin-Kuzmin Suppression
Astrophysics
2012-08-27 v2
Abstract
The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy (UHE) cosmic rays shows a sharp suppression at an energy of eV, consistent with the expected cutoff energy. We observe the ``ankle'' of the cosmic-ray energy spectrum as well, at an energy of eV. We describe the experiment, data collection, analysis, and estimate the systematic uncertainties. The results are presented and the calculation of the statistical significance of our observation is described.
Keywords
Cite
@article{arxiv.astro-ph/0703099,
title = {First Observation of the Greisen-Zatsepin-Kuzmin Suppression},
author = {HiRes Collaboration},
journal= {arXiv preprint arXiv:astro-ph/0703099},
year = {2012}
}
Comments
4 pages, 3 figures, accepted by and to appear in PRL