相关论文: Interactions between Ultra-High-Energy Particles a…
The study of hadronic showers, which are produced by cosmic rays penetrating the Earth's atmosphere, is essential for shedding light on the origins and characteristics of high-energy particles originating from space and reaching our planet.…
Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles…
In a recently proposed model the cosmic rays spectrum at energies above EeV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum. Within this…
The temperature of the cosmic microwave background increases with redshift; at sufficiently high redshift it becomes possible for ultrahigh-energy photons and electrons to produce muons and pions through interactions with background…
The high-energy universe has revealed that energetic particles are ubiquitous in the cosmos and play a vital role in the cultivation of cosmic environments on all scales. Energetic particles in our own galaxy, galactic cosmic rays (GCRs),…
Ultra High Energy Cosmic Rays with energies above ~ 10^18 eV provide an unique window to study hadronic interactions at energies well above those achieved in the largest man-made accelerators. We argue that at those energies string…
Hadrons interaction at high energies is carried out by one color gluon exchange. All quarks and gluons contained in colliding hadrons take part in interaction and production of particles. The contribution of multiple parton interactions is…
We investigate the ionization state of very energetic cosmic ray nuclei in photon fields, such as the cosmic microwave background (CMB) in extragalactic propagation and the environment surrounding the acceleration site in astrophysical…
Moving highly-charged ions carry strong electromagnetic fields that act as a field of photons. In collisions at large impact parameters, hadronic interactions are not possible, and the ions interact through photon-ion and photon-photon…
The production of hard photons and neutral pions in 190 MeV proton induced reactions on C, Ca, Ni, and W targets has been for the first time concurrently studied. Angular distributions and energy spectra up to the kinematical limit are…
Microquasars are potential candidates to produce a non-negligible fraction of the observed galactic cosmic rays. The protons accelerated at the jet termination shock interact with the interstellar medium and may produce detectable fluxes of…
Simple arguments concerning power and acceleration efficiency show that ultra-high energy cosmic rays (UHECRS) with energies >~ 10^{19} eV could originate from GRBs. Neutrons formed through photo-pion production processes in GRB blast waves…
The high rate of star formation and supernova explosions of starburst galaxies make them interesting sources of high energy radiation. Depending upon the level of turbulence present in their interstellar medium, the bulk of cosmic rays…
We show that if the sources of ultra-high energy cosmic rays (UHECRs) with energies E>10^{19}eV are associated with galaxies, then the production of UHECRs must occur in transient events. Our galaxy is currently at a dim state in between…
The presence of ultra-high energy cosmic rays in the universe in the pre-ionization epoch enhances significantly H$_2$ kinetics in virialized halos. It results in more efficient radiative cooling and decreases the lower mass limit of the…
A strong laser field and the Coulomb field of a nucleus can produce e^{+}e^{-} pairs. It is shown for the first time that there is a large probability that electrons and positrons created in this process collide after one or several…
The emergence of habitable conditions on the early Earth and on rocky exoplanets requires persistent energy sources that can drive both prebiotic chemistry and climate warming under magnetically active young G to M stars. To quantify the…
The determination of the primary energy and mass of ultra-high-energy cosmic-rays (UHECR) generating extensive air-showers in the Earth's atmosphere, relies on the detailed modeling of hadronic multiparticle production at center-of-mass…
The flux of neutrinos and photons originating from cosmic ray interactions with the interstellar medium in the galaxy is calculated based on current models for high energy particle interactions. The contribution from a possible dark matter…
Ultrahigh energy protons in magnetic fields produce pions and thus lose energy. The mean free path of such a process is worked out for Gaussian random fields. Two cases are considered: an isotropic and a cylindrically symmetric…