Related papers: Why the knee at 100 PeV could not be seen?
In the last few years several experiments have shown that the cosmic ray spectrum below the knee is not a perfect power-law. In particular, the proton and helium spectra show a spectral hardening by ~ 0.1-0.2 in spectral index at particle…
Primary energy spectral models are tested in the energy range of 1-200 PeV using standardized extensive air shower responses from BASJE-MAS, Tibet, GAMMA and KASCADE scintillation shower arrays. Results point towards the two-component…
After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the `knee' above…
The analysis of cosmic rays fluxes as a function of energy reveals a {\it knee} slightly below $10^{16}$ eV and an {\it ankle} close to $10^{19}$ eV. Their physical origins remain up to now quite enigmatic; in particular, no elementary…
The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of…
Some new developments obtained in the last few years concerning the propagation of high energy cosmic rays are discussed. In particular, it is shown how the inclusion of drift effects in the transport diffusion equations leads naturally to…
We report the high-purity identification of cosmic-ray (CR) protons and a precise measurement of their energy spectrum from 0.15 to 12 PeV using the Large High Altitude Air Shower Observatory (LHAASO). Abundant event statistics, combined…
We present a measurement of the cosmic-ray spectrum above 100\,PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750~m. An inflection of the spectrum is observed, confirming the presence of the…
An analysis is made of the fine structure in the cosmic ray energy spectrum: new facets of present observations and their interpretation and the next step. It is argued that less than about 10% of the intensity of the helium `peak' at the…
A blind search has been made for cosmic ray sources of neutral hadrons yielding a peak just above the knee, which has resulted in possible evidence for a peak at $5.86\pm 0.75 PeV.$ This search was motivated by a 1999 claim by this author…
The differential energy spectrum of cosmic rays exhibits a change of slope, called "knee" of the spectrum, around the nominal energy of 3 x 10^15 eV, and individual "knees" for single ions, at different energies. The present work reports a…
A brief motivation for studying cosmic rays at energies 10^14 < E < 10^17 eV is given. Besides astrophysical interests in identifying and understanding their sources, there are also particle physics aspects related to their transport…
The present experimental status concerning the composition of cosmic rays in the PeV region is reviewed. The results are compared to predictions of contemporary models for the acceleration and propagation of galactic cosmic rays.
We show that the simplest assumptions for the dynamics of particle production allow us to understand the fluxes of hadrons and photons at mountain altitudes as well as the structure of individual events. The analysis requires a heavy…
While from the energetic point of view SNRs are viable sources of Galactic CRs, the issue of whether they can accelerate protons up to PeV remains unsolved. Here we discuss particle acceleration at the forward shock of SN and discuss the…
Existing small, medium and large arrays for the study of cosmic rays of ultra-high energies are aimed for obtaining information about our galaxy and extragalactic space, namely to search and study astronomical objects that produce the flux…
Cosmic rays represent one of the most important energy transformation processes of the universe. They bring information about the surrounding universe, our galaxy, and very probably also the extragalactic space, at least at the highest…
The paper discusses an approach that made it possible to estimate the distance to the nearest pevatrons, which form a knee in the spectrum of the cosmic ray nucleon component of about $4$ PeV. It is based on the spectra of nucleons and…
The propagation of high-energy cosmic rays in the Galaxy is investigated. Solutions of a diffusion model are combined with numerically calculated trajectories of particles. The resulting escape path length and interaction path length are…
We report a measurement of the cosmic ray helium energy spectrum in the energy interval 0.16 -- 13~PeV, derived by subtracting the proton spectrum from the light component~(proton and helium) spectrum obtained with observations made by the…