Related papers: Ultra High-Energy Interaction of CR protons
At energies of a few GeV per nucleon, nuclear collisions exhibit phenomena more complex than the individualistic nucleon interactions observed at much higher energies. From recent results on proton number fluctuations in Au + Au collisions…
Most data gathered from high energy experiments at colliders are analyzed assuming that particles stable enough to not decay in the detector volume, and able to interact strongly or electromagnetically, must be electrons, muons, protons,…
Highlights of the results from ultrarelativistic heavy ion collisions at CERN-SPS are reviewed. In particular, I discuss how the experimental results indicate that a collective strongly interacting system has been produced, and what are the…
Recent experimental results in proton-proton and in proton-nucleus collisions at Large Hadron Collider energies show a strong similarity to those observed in nucleus-nucleus collisions, where the formation of a quark-gluon plasma is…
A very recent observation by the Auger Observatory group claims strong evidence for cosmic rays above 56 EeV being protons from Active Galactic Nuclei. If, as would be expected, the particles above the ankle at about 2 EeV are almost all of…
It is well known that high energy interactions as different as electron-positron annihilation, deep inelastic lepton-nucleon scattering, proton-proton interactions, and nucleus-nucleus collisions have many features in common. Based upon…
The majority of the highest energy cosmic rays are thought to be electrically charged: protons or nuclei. Charged particles experience angular deflections as they pass through galactic and extra-galactic magnetic fields. As a consequence…
Ultra-peripheral collisions of heavy ions and protons are the energy frontier for electromagnetic interactions. Both photonuclear and two-photon collisions are studied, at collision energies that are far higher than are available elsewhere.…
The Pierre Auger collaboration has reported a correlation between Ultra-High Energy Cosmic Rays (UHECR) and nearby Active Galactic Nuclei (AGNs) within 75 Mpc. Two of these events fall within 3 degrees from Centaurus A, the nearest AGN,…
Ultra-high energy cosmic ray (UHECR) protons produced by uniformly distributed astrophysical sources contradict the energy spectrum measured by both the AGASA and HiRes experiments, assuming the small scale clustering of UHECR observed by…
UHE neutrinos may transfer highest cosmic-rays energies overcoming $2.75K^\circ$ BBR and radio-waves opacities (the GZK cut off) from most distant AGN sources at the age of the Universe. These UHE $\nu$ might scatter onto those (light and…
The matter created in Ag+Ag collisions at $\sqrt{s_{NN}}$ = 2.55 GeV, as measured with the HADES experiment, can be characterized by similar thermodynamic quantities as Neutron Star Mergers, thus becoming an essential reference for the…
The origin and chemical composition of ultra high energy cosmic rays is still an open question in astroparticle physics. The observed large-scale isotropy and also direct composition measurements can be interpreted as an extragalactic…
The origin and nature of the ultrahigh energy cosmic rays (UHECRs) are still unknown. However, great progress has been achieved in past years due to the observations performed by the Pierre Auger Observatory and Telescope Array. Above…
Interactions of ultrahigh energy cosmic rays in the surroundings of their accelerators can naturally explain the observed spectrum and composition of UHECRs, including the abundance of protons below the ankle. We show that astrophysical…
Active galactic nuclei (AGNs) have been one of the most widely discussed sources of ultrahigh-energy cosmic rays (UHECRs). The recent results of Pierre Auger observatory (PAO) have indicated a possible composition change of UHECRs above…
Ultraperipheral collisions at collider energies are a useful tool to study photon-hadron (proton/nucleus) and photon-photon interactions in a hitherto unexplored energy regime. Theoretical tools to study these processes are briefly…
We discuss candidates for trans-GZK cosmic rays observed in a variety of detectors. Three types of primaries are represented among the abstracts submitted to this meeting: neutrin os causing a Z-burst, protons arising from the decay of…
The spatial view of the interaction region of colliding high energy protons (in terms of impact parameter) is considered. It is shown that the region of inelastic collisions has a very peculiar shape. It saturates for central collisions at…
Based on a model for the emission of high energy cosmic rays from AGN (Active Galactic Nuclei) that has been proposed by the author, he reviews the status of the GZK cutoff and the correlation of high energy cosmic ray sources with AGN…