Related papers: Ultra High Energy Cosmic Rays
The observation of neutrinos from cosmic accelerators will be revolutionary. High energy neutrinos are closely connected to ultrahigh energy cosmic rays and their sources. Cosmic ray sources are likely to produce neutrinos and the…
This is a review of neutrino astronomy anchored to the observational fact that Nature accelerates protons and photons to energies in excess of $10^{20}$ and $10^{13}$ eV, respectively. Although the discovery of cosmic rays dates back close…
Over the last third of the century, a few tens of events, detected by ground-based cosmic ray detectors, have opened a new window in the field of high-energy astrophysics. These events have macroscopic energies, unobserved sources, an…
We review the current state and future prospect of ultra high energy cosmic ray physics and the relationship between cosmic rays and gamma-ray astrophysics.
The origin of the highest-energy cosmic rays remains a mystery. The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions have strongly constrained most models…
We address some current theoretical issues around ultra-high energy cosmic rays. We recall that scenarios producing more gamma-rays than cosmic rays up to high redshift can in general only provide a sub-dominant contribution to the…
While there is some level of consensus on a Galactic origin of cosmic rays up to the knee ($E_{k}\sim 3\times 10^{15}$ eV) and on an extragalactic origin of cosmic rays with energy above $\sim 10^{19}$ eV, the debate on the genesis of…
We study the large-scale distribution of the arrival directions of the highest energy cosmic rays observed by various experiments. Despite clearly insufficient statistics, we find a deficit of cosmic rays at energies higher than 10^{20} eV…
We report an estimation of the injected mass composition of ultra-high energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-dependent sky distribution of UHECR events observed by the…
We briefly discuss some open problems and recent developments in the investigation of the origin and propagation of ultra high energy cosmic rays (UHECRs).
Our knowledge of the mass composition of cosmic rays is deficient at all energies above 10^17. Here systematic differences between different measurements are discussed and, in particular, it is argued that there is no compelling evidence to…
Extremely high energy (up to 10**(22) eV) cosmic neutrino beams initiate high energy particle cascades in the background of relic neutrinos from the Big Bang. We perform numerical calculations to show that such cascades could contribute…
The impressive power-law decay of the energy spectrum of cosmic rays over more than thirty orders of magnitude in intensity and for energies ranging over eleven decades between $\simeq 10^9 $eV and $\simeq 10^{20} $eV is actually dotted…
We will review the main physical aspects of Ultra High Energy Cosmic Rays. We will discuss in particular their propagation through astrophysical backgrounds, focusing on the latest experimental observations of HiRes, Telescope Array and…
Cosmic high energy neutrinos are inextricably linked to the origin of cosmic rays which is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed possess macroscopic energies and their…
The properties of galactic cosmic rays are investigated with the KASCADE-Grande experiment in the energy range between $10^{14}$ and $10^{18}$ eV. Recent results are discussed. They concern mainly the all-particle energy spectrum and the…
We compute the ultra-high energy cosmic ray horizon, i.e. the distance up to which cosmic ray sources may significantly contribute to the fluxes above a certain threshold on the observed energies. We obtain results both for proton and heavy…
Recent measurements of ultra-high energy cosmic rays and neutrinos are briefly reviewed. With several new large scale observatories nearing completion or becoming fully operational only very recently, a large body of high quality and high…
The physics of Ultra High Energy Cosmic Rays will be reviewed, discussing the latest experimental results and theoretical models aiming at explaining the observations in terms of spectra, mass composition and possible sources. It will be…
We explore scenarios where the highest energy cosmic rays (HECR) are produced by new particle physics near the grand unification scale. Using detailed numerical simulations of extragalactic cosmic and gamma-ray propagation, we show the…