Cosmic Ray Energy Spectra and Mass Composition at the Knee - Recent Results from KASCADE -

Abstract

Recent results from the KASCADE experiment on measurements of cosmic rays in the energy range of the knee are presented. Emphasis is placed on energy spectra of individual mass groups as obtained from an two-dimensional unfolding applied to the reconstructed electron and truncated muon numbers of each individual EAS. The data show a knee-like structure in the energy spectra of light primaries (p, He, C) and an increasing dominance of heavy ones (A > 20) towards higher energies. This basic result is robust against uncertainties of the applied interaction models QGSJET and SIBYLL which are used in the shower simulations to analyse the data. Slight differences observed between experimental data and EAS simulations provide important clues for further improvements of the interaction models. The data are complemented by new limits on global anisotropies in the arrival directions of CRs and by upper limits on point sources. Astrophysical implications for discriminating models of maximum acceleration energy vs galactic diffusion/drift models of the knee are discussed based on this data.

arXiv comment8 pages, 7 figures, to appear in Nuclear Physics B, Proceedings Supplements, as part of the volume for the CRIS 2004, Cosmic Ray International Seminar: GZK and Surroundings

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Cited by in corpus (8)

• The Astrophysics of Ultrahigh Energy Cosmic Rays
• Lorentz Invariance Violation and Chemical Composition of Ultra High Energy Cosmic Rays
• The Fermi Bubble as a Source of Cosmic Rays in the Energy Range > 10E15 eV
• The nature of the 'knee' in the cosmic ray energy spectrum
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• Ultra-high energy cosmic rays: from GeV to ZeV
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