Related papers: Cosmic ray knee and new physics at the TeV scale
Recent observations of cosmic ray electrons from several instruments have revealed various degrees of deviation in the measured electron energy distribution from a simple power-law, in a form of an excess around TeV energies. An even more…
We introduce neutrino astronomy from 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 to a century, we…
The energy spectrum of cosmic rays between 10**16 eV and 10**18 eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is…
The origin and nature of ultrahigh-energy cosmic ray events, above the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy, constitute a long-standing, unsolved mistery. Neutrinos are proposed candidates but their standard interactions with matter…
Below the knee in the cosmic ray spectrum, balloon and spacecraft experiments offer the capability of direct composition and energy measurements on the primary particles. A major difficulty is obtaining enough exposure to extend the range…
The existence of nearby discrete cosmic-ray sources can lead to many interesting effects on the observed properties of cosmic rays. Recent measurements of cosmic rays with the CALET and the DAMPE experiments have revealed a bump-like new…
If supernova remnants (SNRs) are the sites of cosmic-ray acceleration, the associated nuclear interactions should result in observable fluxes of TeV gamma-rays from the nearest SNRs. Measurements of the gamma-ray flux from six nearby,…
Recent results of advanced experiments with sophisticated measurements of cosmic rays in the energy range of the so called knee at a few PeV indicate a distinct knee in the energy spectra of light primary cosmic rays and an increasing…
Data obtained in the ATIC-2 (Advanced Thin Ionization Calorimeter), CREAM (Cosmic Ray Energetics and Mass)) and PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) experiments suggest that elemental interstellar…
Extragalactic cosmic ray protons with an injection spectrum of the type $E^{-2.7}$ show a spectrum on earth with a dip due to the Bethe-Heitler pair production against the photons of the cosmic microwave background. The dip is produced in…
We reconsider the scenario in which the knee in the cosmic ray spectrum is explained as due to a change in the escape mechanism of cosmic rays from the Galaxy from one dominated by transverse diffusion to one dominated by drifts. We solve…
Changes of the cosmic-ray mass composition at the `knee' of the cosmic-ray flux spectrum near 10^{15} eV energy are investigated using data from ten Cosmic Ray Tracking (CRT) detectors and the HEGRA air-shower array on La Palma, Canary…
Very recently the IceCube Collaboration has reported an observation of 28 neutrino candidates with energies between 50 TeV and 2 PeV, constituting a 4.1$\sigma$ excess compared to the atmospheric background. In this article we investigate…
We investigate the possibility that the cosmic ray (CR) knee is entirely explained by the energy-dependent CR leakage from the Milky Way. We test this hypothesis calculating the trajectories of individual CRs with energies between…
The ARGO--YBJ experiment has been in stable data taking for more than five years at the Yangbajing cosmic ray observatory (Tibet, P.R. China, 4300 m a.s.l.). The detector collected about $5\times10^{11}$ events in a wide energy range from…
Blazars are potential candidates of cosmic-ray acceleration up to ultrahigh energies ($E\gtrsim10^{18}$ eV). For an efficient cosmic-ray injection from blazars, $p\gamma$ collisions with the extragalactic background light (EBL) and cosmic…
We present a self-consistent interpretation of the of very-high-energy neutrino signal from the direction of the inner Galaxy, which is a part of the astronomical neutrino signal reported by IceCube. We demonstrate that an estimate of the…
Cosmic rays (CRs) are charged particles that arrive at Earth isotropically from all directions and interact with the atmosphere. The presence of a spectral knee feature seen in the CR spectrum at $\sim$3 PeV energies is an evidence that…
The existence of extra dimensions allows the possibility that the fundamental scale of gravity is at the TeV. If that is the case, gravity could dominate the interactions of ultra-high energy cosmic rays. In particular, the production of…
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…