Related papers: Cosmic Ray particle production
We show that photoproduction cross sections recently measured by ZEUS and H-1 at HERA energies$^1$ are in agreement with our earlier prediction based on high-energy hadronic structure of the photon in the QCD minijet-type model$^2$. We…
The influence of high and low energy hadronic models on lateral distribution functions of cosmic ray air showers for AUGER energies is explored. A large variety of presently used high and low energy hadron interaction models are analysed…
The theory of diffusive particle acceleration explains the spectral properties of the cosmic rays below energies of approx. 10^6 GeV as produced at strong shocks in supernova remnants (SNR's). To supply the observed flux of cosmic rays, a…
The recently proposed states of low energy provide a well-motivated class of reference states for the quantized linear scalar field on cosmological Friedmann-Robertson-Walker spacetimes. The low energy property of a state is localized close…
We present an introductory lecture on general features of cosmic rays, for non-experts, and some recent developments concerning cascade equations for air shower developments.
We review the experimental evidences about flux and mass composition of ultra high energy cosmic rays in connection with theoretical scenarios concerning astrophysical sources. In this context, we also address the discussion about the…
In this paper we apply to photoproduction total cross-section a model we have proposed for purely hadronic processes and which is based on QCD mini-jets and soft gluon re-summation. We compare the predictions of our model with the HERA data…
We propose that neutrons may be generated in high-energy, high-flux photon environments via photo-induced reactions on pre-existing baryons. These photohadronic interactions are expected to occur in astrophysical jets and surrounding…
We present a study of the multiplicities, of the lateral distributions and of the ratio of the electromagnetic to the hadronic components in the air showers, generated by the collision in the atmosphere of an incoming high energy cosmic ray…
Cosmic Ray (CR) acceleration still challenges the researchers. Fast particles may be accelerated in astrophysical environments by a variety of processes. Acceleration in magnetic reconnection sites in particular, has lately attracted the…
Laboratory experiments to explore plasma conditions and stimulated particle acceleration can illuminate aspects of the cosmic particle acceleration process. Here we discuss the cosmic-ray candidate source object variety, and what has been…
Galaxies at high redshifts with strong star formation are sources of high-energy cosmic rays. These cosmic rays interact with the baryon and radiation fields of the galactic environment via photo-pair, photo-pion and proton-proton processes…
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 experimental observations on the `bulk' features of particle production at high (pseudo)rapidities will be reviewed. This kinematic region is of interest mostly because of its relevance to the theoretical description of initial state…
In this paper, analogies between multiparticle production in high-energy collisions and the time evolution of the early universe are discussed. A common explanation is put forward under the assumption of an unconventional early state: a…
The origin of the highest energy cosmic rays is still unknown. The discovery of their sources will reveal the workings of the most energetic astrophysical accelerators in the universe. Current observations show a spectrum consistent with an…
We shortly discuss several astrophysical scenarios leading to cosmic ray acceleration up to extremely high energies reaching the scale of 10^{20} eV. The processes suggested in the literature include acceleration at relativistic jet…
Cosmic ray (CR) transport and acceleration is essential for many astrophysical problems, e.g., CMB foreground, ionization of molecular clouds and all high energy phenomena. Recent advances in MHD turbulence call for revisions in the…
Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal and dynamical evolution. The purpose of this work is to explore the possibility that a low-energy component of…
We discuss that hadron-induced atmospheric air showers from ultra-high energy cosmic rays are sensitive to QCD interactions at very small momentum fractions x where nonlinear effects should become important. The leading partons from the…