Upturn observed in heavy nuclei to iron ratios by the ATIC-2 experiment
High Energy Astrophysical Phenomena
2013-03-26 v1
Abstract
The ratios of fluxes of heavy nuclei from sulfur (Z=16) to chromium (Z=24) to the flux of iron were measured by the ATIC-2 experiment. The ratios are decreasing functions of energy from 5 GeV/n to approximately 80 GeV/n, as expected. However, an unexpected sharp upturn in the ratios are observed for energies above 100 GeV/n for all elements from Z=16 to Z=24. Similar upturn but with lower amplitude was also discovered in the ATIC-2 data for the ratio of fluxes of abundant even nuclei (C, O, Ne, Mg, Si) to the flux of iron. Therefore the spectrum of iron is significantly different from the spectra of other abundant even nuclei.
Cite
@article{arxiv.1303.6108,
title = {Upturn observed in heavy nuclei to iron ratios by the ATIC-2 experiment},
author = {A. D. Panov and N. V. Sokolskaya and V. I. Zatsepin and J. H. Adams and H. S. Ahn and G. L. Bashindzhagyan and J. Chang and M. Christl and A. R. Fazely and T. G. Guzik and J. Isbert and K. C. Kim and E. N. Kouznetsov and M. I. Panasyuk and E. S. Seo and J. W. Watts and J. P. Wefel and J. Wu},
journal= {arXiv preprint arXiv:1303.6108},
year = {2013}
}
Comments
4 pages, LaTeX2e, a paper for 23rd European Cosmic Ray Symposium (2012)