We introduce a static toy model of the cosmic ray (CR) universe in which cosmic ray propagation is taken to be diffusive and cosmic ray sources are distributed randomly with a density the same as that of local L∗ galaxies, 5 × 10 −3 Mpc. These sources “fire” at random times through the history of the universe but with a set expectation time for the period between bursts. Our toy model model cap...

Cosmic rays scatter off magnetic irregularities (Alfvén waves) with which they are resonant, that is, waves of wavelength comparable to their gyroradii. These waves may be generated either by the cosmic rays themselves, if they stream faster than the Alfvén speed, or by sources of MHD turbulence. Waves excited by streaming cosmic rays are ideally shaped for scattering, whereas the scattering ef...

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for substantial revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to calculate the scattering frequency for cosmic rays in the ISM. We consider gyroresonance with MHD modes (Alfvénic, slow and fast) and transit-time damping (TTD) by fast modes. We provi...

Statistical arguments show that the volumeand time-averaged kinetic power of GRBs and fireball transients (FTs) into an L galaxy like the Milky Way is at the level of 10 ergs s. This number, though with wide uncertainties related to the internal or external shock efficiency, is sufficient to power hadronic cosmic rays observed locally. The release of energy by the high-mass progenitor stars of ...

The interaction cross-section is one of the fundamental properties of any elementary particle. For decades, only accelerator measurements of the particle cross-sections were available. Crosssection measurements at higher and higher energy become possible as more and more powerful accelerators are introduced. However, cosmic rays not only provide a constant flux of ultra highenergy particles, bu...

A bstract In this work, we discuss the possibility to test Heavy Neutral Leptons (HNLs) using “Cosmic Ray Beam Dump” experiments. analogy with terrestrial beam dump experiments, where a first hits target and is then absorbed by shield, consider high-energy incident cosmic rays impinging on Earth’s atmosphere surface. We focus here HNL production from atmospherically produced kaon, pion D -meson...