Related papers: Unparticle effects on cosmic ray photon and $e^\pm…
We discuss the intergalactic propagation of ultra-high-energy cosmic rays (UHECRs) with energies E \geq 10^{18.5} eV. We consider the propagation of UHECRs under the influence of the energy-dependent deflection by a weak random magnetic…
Recent measurements of the cosmic microwave background confirm that it is described by a Planckian distribution with high precision. It is non-extensivity bounded to be less than some parts in $10^5$, or to some parts in $10^4$ at most.…
Stochasticity effects in the spin (de)polarization of an ultrarelativistic electron beam during photon emissions in a counterpropoagating ultrastrong focused laser pulse in the quantum radiation reaction regime are investigated. We employ a…
We give a compact expression for the unpolarised differential cross section for muon-proton scattering in the one photon exchange approximation. The effect of adding the vacuum polarisation amplitude to the no-spin-flip amplitude for one…
The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic…
We consider emission of a photon by an electron in the field of a strong laser wave. Polarization effects in this process are important for a number of physical problems. We discuss a probability of this process for circularly polarized…
The existence of scale invariant physics would lead to new phenomena in particle physics that could be detected at the LHC. In this paper we exploit the effects of these unparticles in $WW \to WW$ scattering. From the requirement of…
Electromagnetism becomes a nonlinear theory having (effective) photon-photon interactions due at least to electron-positron fluctuations in the vacuum. We discuss the consequences of the nonlinearity for the force felt by a charge probe…
The cosmic ray energy spectra encode very important information about the mechanisms that generate relativistic particles in the Milky Way, and about the properties of the Galaxy that control their propagation. Relativistic electrons and…
Cosmic-rays with energies up to $3\times10^{20}$ eV have been observed, as have as have astrophysical neutrinos with energies above 1 PeV. In this talk, I will discuss some of the unique phenomena that occur when particles with TeV energies…
We study the impact on the trajectory of high-energy cosmic-ray protons of scattering off the cosmic dark matter. We compute the scattering angle as a function of the cosmic-ray energy, of the dark matter mass, and of the interaction…
The process of Compton scattering $\gamma e^{\pm} \to \gamma e^{\pm}$ in a strongly magnetized medium of arbitrary temperature and zeroth chemical potential was considered. The analytical expressions for the partial cross section in the…
The backward Compton scattering is a basic process at future higher energy photon colliders. To obtain a high probability of e->gamma conversion the density of laser photons in the conversion region should be so high that simultaneous…
Nonlinear phenomena of lepton-photon interactions in external backgrounds with a generalised periodic plane-wave geometry are studied. We discuss nonlinear Compton scattering in head-on lepton-photon collisions extended properly to beyond…
We develop the concept of scattering matrix and we use it to perform stable numerical calculations of photo-emission from nano-tips. Electrons move in an external space and time dependent nonperturbative electric field. We apply our…
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 fraction of positrons and electrons in cosmic rays recently observed on the International Space Station unveiled an unexpected excess of the positrons, undermining the current foundations of cosmic rays sources. We provide a quantum…
Data of Pierre Auger Observatory show a proton-dominated chemical composition of ultrahigh-energy cosmic rays spectrum at (1 - 3) EeV and a steadily heavier composition with energy increasing. In order to explain this feature we assume that…
Impacts of spin-polarization of an ultrarelativistic electron beam head-on colliding with a strong laser pulse on emitted photon spectra and electron dynamics have been investigated in the quantum radiation regime. We simulate photon…
The elastic scattering of two real photons in vacuum is one of the most elusive of the fundamentally new processes predicted by quantum electrodynamics. This explains why, although it was first predicted more than eighty years ago, it has…