Evolution of the cosmic ray anisotropy above 10^{14} eV
Abstract
The amplitude and phase of the cosmic ray anisotropy are well established experimentally between 10^{11} eV and 10^{14} eV. The study of their evolution into the energy region 10^{14}-10^{16} eV can provide a significant tool for the understanding of the steepening ("knee") of the primary spectrum. In this letter we extend the EAS-TOP measurement performed at E_0 around 10^{14} eV, to higher energies by using the full data set (8 years of data taking). Results derived at about 10^{14} and 4x10^{14} eV are compared and discussed. Hints of increasing amplitude and change of phase above 10^{14} eV are reported. The significance of the observation for the understanding of cosmic ray propagation is discussed.
Cite
@article{arxiv.0901.2740,
title = {Evolution of the cosmic ray anisotropy above 10^{14} eV},
author = {M. Aglietta and V. V. Alekseenko and B. Alessandro and P. Antonioli and F. Arneodo and L. Bergamasco and M. Bertaina and R. Bonino and A. Castellina and A. Chiavassa and B. D'Ettorre Piazzoli and G. Di Sciascio and W. Fulgione and P. Galeotti and P. L. Ghia and M. Iacovacci and G. Mannocchi and C. Morello and G. Navarra and O. Saavedra and A. Stamerra and G. C. Trinchero and S. Valchierotti and P. Vallania and S. Vernetto and C. Vigorito},
journal= {arXiv preprint arXiv:0901.2740},
year = {2009}
}
Comments
4 pages, 3 figures, accepted for publication on ApJ Letters