Related papers: On parton distributions in a photon gas
We demonstrate by numerical flux calculations that neutrino beams producing the observed highest energy cosmic rays by weak interactions with the relic neutrino background require a non-uniform distribution of sources. Such sources have to…
We investigate the phenomenology of nonlinear Compton scattering of polarised photons by unpolarised electrons in plane-wave backgrounds. The energy and angular spectra of polarised photons are calculated for linearly- and…
Nature produces cosmic ray particles, probably protons, with energies well above $10^{20}$ eV -- how are they produced? Where do they come from? Gamma rays with energies above $10^{13}$ eV are produced in jets of active galaxies -- are…
Isotopic distributions for light particles and intermediate mass fragments have been measured for 112Sn+112Sn, 112Sn+124Sn, 124Sn+112Sn and 124Sn+124Sn collisions at E/A=50 MeV. Isotope, isotone and isobar yield ratios are utilized to…
The collisions between accelerated protons and the photons present in cosmos can be a main source of high-energy neutrinos (E \geq 10^6 GeV) of all flavors above the atmospheric neutrino background. I discuss here the possibility of…
The general structure of the cross section of $\gamma N$ scattering with polarized photon and/or nucleon in initial and/or final state is systematically described and exposed through invariant amplitudes. A low-energy expansion of the cross…
We consider the possibility that the particles in the Ultra High Energy Cosmic Rays arriving to Earth might be neutrons instead of protons. We stress that in such case the argument for the GZK cutoff is weaker and that it is conceivable…
I give a brief critical review of the predicted intensity of diffuse high energy neutrinos of astrophysical origin over the energy range from 10^12 eV to 10^24 eV. Neutrinos from interactions of galactic cosmic rays with interstellar matter…
We present a new concept of nonlinear dynamics of incoherent superstrong radiation in plasmas. Recently we have disclosed a novel mechanism of the establishment of equilibrium between a photon and a dense photon bunch through the exchange…
Multiple parton interactions in a single proton-proton collision are expected to play an important role for many observables at LHC. To a large part their phenomenological description relies on rather simple and physically intuitive…
The high energy neutrino signature from proton-proton and photo-meson interactions in a supernova remnant shell ejected prior to a gamma-ray burst provides a test for the precursor supernova, or supranova, model of gamma-ray bursts. Protons…
Sources of ultrahigh energy photons operating at high red shift produce a diffuse background of neutrinos. At high red shift, when the cosmic microwave background radiation has a higher temperature, an electromagnetic cascade originated by…
We show how the photon input parton distribution function (PDF) may be calculated with good accuracy, and used in an extended DGLAP global parton analysis in which the photon is treated as an additional point-like parton. The uncertainty of…
We calculate the flux of neutrinos generated by the propagation of ultra-high energy nuclei over cosmological distances. The propagation takes into account the interactions with cosmic background radiations including the CMB and the most…
We have extended recently proposed model of parton distribution i nucleons to the case of nucleons in nuclei.
In this paper we review the status of the search for high-energy neutrinos from outside the solar system and discuss the implications for the origin and propagation of cosmic rays. Connections between neutrinos and gamma-rays are also…
A recently developed model for $\rho$-meson propagation in dense hadronic matter is applied to total photoabsorption cross sections in $\gamma$-proton and $\gamma$-nucleus reactions. Within the vector dominance model the photon coupling to…
More than 100 years after the discovery of cosmic rays and various experimental efforts, the origin of ultra-high energy cosmic rays (E > 100 PeV) remains unclear. The understanding of production and propagation effects of these highest…
We will review the production of neutrinos with PeV energies and above. Discussing two possible sources of this radiation: the propagation of ultra high energy cosmic rays and the decay of super heavy dark matter. The discussion will focus…
Low energy experiments with photons can provide deep insights into fundamental physics. In this note we concentrate on minicharged particles. We discuss how they can arise in extensions of the standard model and how we can search for them…