arXiv subjects

Roman Raikin

Publications and source records attributed to Roman Raikin.

3 recordsLinked to original sources

arXiv2019

Spectra of protons and nuclei in the energy range of ${10^{10}\div10^{20}}$ eV in the framework of Galactic cosmic ray origin

We consider the problem of the cosmic ray spectrum formation assuming that cosmic rays are produced by Galactic sources. The anomalous diffusion equation proposed in our recent papers is used to describe cosmic ray propagation in the interstellar medium. We show that in the framework of this approach and with generation spectrum exponent $γ=2.85$ it is possible to reproduce locally observed basic features of cosmic rays in the energy region of $10^{10}÷10^{20}$ eV: difference between spectral exponents of protons and other nuclei, mass composition variation, `knee' problem, flattening of the primary spectrum at $E \geq 10^{18}÷10^{19}$ eV. The crucial model predictions for the mass composition behaviour in the ultra-high energy region are discussed.

astro-ph.HE↗

arXiv2018

Lateral distributions of electrons in air showers initiated by ultra-high energy gamma quanta taking into account LPM and geomagnetic field effects

Lateral distributions of electrons in air showers initiated by photons of ultra high energies ($10^{18}-10^{22}$ eV) obtained on the basis of numerical solution of adjoint cascade equations are presented. An extended analysis has been made considering separately the Landau-Pomeranchuk-Migdal (LPM) effect and the interaction of photons and electrons with the geomagnetic field (GMF) with respect to the scaling formalism for lateral distributions. It is shown that one-parametric scaling description of the lateral distribution of electrons remains valid up to the highest energies considering the LPM and GMF effects, that allow effective primary particle type discrimination using the surface detectors data of largest ground-based air shower arrays.

astro-ph.HE↗

arXiv2018

On the efficiency of the evaluation of the primary cosmic ray composition using lateral distributions of air shower electromagnetic component

New analysis of lateral distributions (LD) of electrons, muons and charged particles in extensive air showers generated by $10^{15}-10^{19}$ eV cosmic rays has been made with respect to the scaling formalism for LD and air shower universality paradigm. It is found that lateral distributions of electrons and muons, when considered separately, are well described by one-parametric scaling functions, while for the charged particles mixture distributions the scaling description is not accurate in radial distance range where electrons and muons give a comparable contribution to the local particle densities. The use of scaling formalism enables enhancing the electron/muon separation capabilities and, when combined with theoretically motivated air shower universality concept, provides robust mass composition estimates. The proposed approach could be implemented for the present and future (multi-) hybrid air shower observations, especially in realizing the potential of Auger and Telescope Array observatories upgrades, as well as for re-analysis and cross-calibration of the data collected from different air shower arrays in a broad primary energy range.

astro-ph.HE↗