Related papers: Remarks on the chemical composition of highest-ene…
We present arguments aiming at reconciling apparently contradictory results concerning the chemical composition of cosmic rays of highest energy, coming recently from the Auger and HiRes collaborations. In particular, we argue that the…
We study basic characteristics of distributions of the depths of shower maximum in air showers caused by cosmic rays with the highest energies. The consistency between their average values and widths, and their energy dependences are…
We apply statistical inference on the Pierre Auger Open Data to discern for the first time the full mass composition of cosmic rays at different energies. Working with longitudinal electromagnetic profiles of cosmic ray showers, in…
The chemical composition of ultra high energy cosmic rays is still uncertain. The latest results obtained by the Pierre Auger Observatory and the HiRes Collaboration, concerning the measurement of the mean value and the fluctuations of the…
The greater part of this paper is concerned with a historical discussion of the development of the search for the origins of the highest-energy cosmic-rays together with a few remarks about future prospects. Additionally, in section 6, the…
The mass composition of ultra-high-energy cosmic rays is an open problem in astroparticle physics. It is usually inferred from the depth of the shower maximum (Xmax) of cosmic-ray showers, which is only ambiguously determined by modern…
The origin and nature of ultra high energy cosmic rays remains being a mystery. However, great progress has been made in recent years due to the observations performed by the Pierre Auger Observatory and Telescope Array. In particular, it…
A review of several analyses is presented that forces the conclusion that the mass composition of the highest-energy cosmic rays is not proton-dominated. This deduction, combined with the use of a modern hadronic interaction model, should…
The shape of the longitudinal development of the showers generated in the atmosphere by very high energy cosmic ray particles encodes information about the mass composition of the flux, and about the properties of hadronic interactions that…
Studies of the composition of the highest energy cosmic rays with the Pierre Auger Observatory, including examination of hadronic physics effects on the structure of extensive air showers. Submissions to the 31st ICRC, Lodz, Poland (July…
We argue that the data published by the Pierre Auger Collaboration (arXiv:0711.2256) disfavor at 99% confidence level their hypothesis that most of the highest-energy cosmic rays are protons from nearby astrophysical sources, either Active…
At present there are still several open questions about the origin of the ultra high energy cosmic rays. However, great progress in this area has been made in recent years due to the data collected by the present generation of ground based…
Although recent measurements of the shower profiles of ultra-high energy cosmic rays suggest that they are largely initiated by heavy nuclei, such conclusions rely on hadronic interaction models which have large uncertainties. We…
Recent results from Pierre Auger Observatory, showing energy dependent chemical composition of ultrahigh-energy cosmic rays (UHECRs) with a growing fraction of heavy elements at high energies, suggest a possible non-negligible contribution…
Observations of cosmic rays have been improving at all energies, with higher statistics and reduced systematics. Fundamental questions remain regarding the origins of cosmic rays both within the Galaxy and in extragalactic sources, and new…
The flux and nuclear composition of ultra-high energy cosmic rays depend on the cosmic distribution of their sources. Data from cosmic ray observatories are yet inconclusive about their exact location or distribution, but provide a measure…
The present situation with regard to experimental data on ultra high-energy cosmic rays is briefly reviewed. Whilst detailed knowledge of the shape of the energy spectrum is still lacking, it is clear that events above 10^20 eV do exist.…
The scientific achievements of the Pierre Auger Collaboration cover diverse and complementary fields of research. The search for the origin of ultra-high energy cosmic rays (UHECRs) is based on the measurement of the energy spectrum and…
A brief review about the chemical composition of cosmic rays in the energy range 10^15 < E < 10^20 eV is given. While there is convincing evidence for an increasingly heavier composition above the knee, no clear picture has emerged at the…
We explore the feasibility of estimating primary cosmic ray composition at ultra high energies from the sum of muon, electron and photon densities and the depth of maximum of extensive air showers detected by the Auger Observatory. From the…