Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV pose a conundrum, the solution of which requires either drastic revision of our astrophysical understanding, or new physics beyond the Standard Model. Nucleons of such energies must originate within the local supercluster in order to avoid excessive energy losses through photopion production on the cosmic microwave background. However they do not point back towards possible nearby sources, e.g. the active galaxy Cen A or M87 in the Virgo cluster, so such an astrophysical origin requires intergalactic magnetic fields to be a hundred times stronger than previously believed, in order to isotropise their arrival directions. Alternatively the pri...
Ultra high energy cosmic rays (UHECR) pose a problem either for particle physics or for astrophysics...
UHE neutrinos may transfer highest cosmic-rays energies overcoming $2.75K^\circ$ BBR and radio-waves...
Cosmic rays may provide opportunities for probing fundamental physics. For example, ultrahigh-energy...
Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV...
The rarest cosmic rays above the GZK cut'off $(E_{CR} \tilde{>} 10^{19} \div 10^{20} eV)$ are probab...
The rarest cosmic rays above the GZK cut'off $(E_{CR} \tilde{>} 10^{19} \div 10^{20} eV)$ are probab...
We discuss theoretical issues and experimental data that brought the ultra high energy cosmic rays i...
Observations of cosmic rays with energies above ~ 4 x 10^{10} GeV have inspired several speculative ...
Resonant photopion production with the cosmic microwave background predicts a suppression of extraga...
Observations of cosmic rays with energies above ~ 4 x 10^{10} GeV have inspired several speculative ...
Resonant photopion production with the cosmic microwave background predicts a suppression of extraga...
A re-examination of the energy cosmic ray spectrum above $10^{20}$ eV is presented. The overall data...
In early years the cosmic ray studies were ahead of accelerator research, starting from the discover...
The expected proton and neutrino fluxes from decays of massive metastable relic particles is calcula...
The most energetic particles ever detected exceed $10^{20}$ eV in energy. Their existence represents...
Ultra high energy cosmic rays (UHECR) pose a problem either for particle physics or for astrophysics...
UHE neutrinos may transfer highest cosmic-rays energies overcoming $2.75K^\circ$ BBR and radio-waves...
Cosmic rays may provide opportunities for probing fundamental physics. For example, ultrahigh-energy...
Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV...
The rarest cosmic rays above the GZK cut'off $(E_{CR} \tilde{>} 10^{19} \div 10^{20} eV)$ are probab...
The rarest cosmic rays above the GZK cut'off $(E_{CR} \tilde{>} 10^{19} \div 10^{20} eV)$ are probab...
We discuss theoretical issues and experimental data that brought the ultra high energy cosmic rays i...
Observations of cosmic rays with energies above ~ 4 x 10^{10} GeV have inspired several speculative ...
Resonant photopion production with the cosmic microwave background predicts a suppression of extraga...
Observations of cosmic rays with energies above ~ 4 x 10^{10} GeV have inspired several speculative ...
Resonant photopion production with the cosmic microwave background predicts a suppression of extraga...
A re-examination of the energy cosmic ray spectrum above $10^{20}$ eV is presented. The overall data...
In early years the cosmic ray studies were ahead of accelerator research, starting from the discover...
The expected proton and neutrino fluxes from decays of massive metastable relic particles is calcula...
The most energetic particles ever detected exceed $10^{20}$ eV in energy. Their existence represents...
Ultra high energy cosmic rays (UHECR) pose a problem either for particle physics or for astrophysics...
UHE neutrinos may transfer highest cosmic-rays energies overcoming $2.75K^\circ$ BBR and radio-waves...
Cosmic rays may provide opportunities for probing fundamental physics. For example, ultrahigh-energy...