Related papers: On parton distributions in a photon gas
Photons resulting from jet-medium interactions offer the opportunity of studying the evolving quark distribution in a heavy ion collision. The spectra of jet-medium photons is presented within the JETSCAPE framework for two different energy…
A cubic kilometer scale experiment has been proposed to detect cosmic neutrinos of energy from tens of GeV up to the highest energies observed for cosmic rays, around 10**20 eV, or possibly even beyond. Detection efficiencies depend…
The physics of Ultra High Energy Cosmic Rays will be reviewed, discussing the latest experimental results and theoretical models aiming at explaining the observations in terms of spectra, mass composition and possible sources. It will be…
A discussion is presented of the manner in which uncertainties in parton distributions and related quantities are determined. One of the central problems is the criteria used to judge what variation of the parameters describing a set of…
Optimum nuclear parton distributions are determined by an analysis of muon and electron deep inelastic scattering data. Assuming simple A dependence and polynomial functions of x and 1-x for nuclear modification of parton distributions, we…
Neutrino-nucleon total cross sections for neutrino energies up to ultrahigh energies (UHE), E_\nu=10^12 GeV, are evaluated within the framework of the dynamical (radiative) parton model. The expected uncertainties of these predictions do…
We study the distribution of the energy of the protons that can produce an astrophysical neutrino with a given observed energy, in the TeV--PeV range, both through $pp$ or $p\gamma$ interactions. Due to the increasing multiplicity of the…
The temperature of the cosmic microwave background increases with redshift; at sufficiently high redshift it becomes possible for ultrahigh-energy photons and electrons to produce muons and pions through interactions with background…
I give a brief discussion of possible sources of high energy neutrinos of astrophysical origin over the energy range from $\sim 10^{12}$ eV to $\sim 10^{25}$ eV. In particular I shall review predictions of the diffuse neutrino intensity.…
We compute the hard photon production rate of a chemically non-equilibrated quark-gluon plasma. We assume that the plasma is already thermally equilibrated, i.~e. describable by a temperature, but with a phase-space distribution that…
The electromagnetic processes of Compton scattering and photon splitting/merging are investigated in the presence of strongly magnetized electron-positron plasma. The influence of these processes on the radiation transfer in the…
The feasibility of an experimental determination of the parton distributions of virtual photons at high energy $ep$ colliders is studied in the context of the DESY-HERA collider. Recently proposed parton densities of virtual photons are…
The field of high energy particle astronomy is exciting and rapidly developing. In the last few years, we have detected extragalactic sources of intense TeV gamma radiation and individual cosmic ray particles with energies exceeding 25…
The radiation transport problem in the plane-parallel medium with the large velocity gradient is considered. The Sobolev approximation is used. The effects of continuum absorption and line overlap are taken into account. The photon loss…
In this article, based on the talk given at the Cracow Epiphany Conference on Astroparticle Physics, I discuss some of the opportunities provided by high-energy and ultra-high energy neutrino astronomy in probing particle physics beyond the…
Recent progress on the parton distribution functions of the photon, both real and virtual, is briefly reviewed and experimental possibilities at HERA are discussed.
Reliable knowledge of parton distributions at large x is crucial for many searches for new physics signals in the next generation of collider experiments. Although these are generally well determined in the small and medium x range, it has…
We propose a generic ansatz for the extension of parton distributions of the real photon to those of the virtual photon. Alternatives and approximations are studied that allow closed-form parametrizations.
The luminosity distribution in the effective $\gamma\gamma$ mass at photon collider has usually two peaks which are well separated: high energy peak with mean energy spread 5-7% and wide low energy peak.The low energy peak depends strongly…
Photon-photon scattering, due to photons interacting with virtual electron-positron pairs, is an intriguing deviation from classical electromagnetism predicted by quantum electrodynamics (QED). Apart from being of fundamental interest in…