Related papers: SUSY Scaling Violations and UHECR
Ultra high energy cosmic rays (UHECRs) may interact with photon backgrounds and thus the universe is opaque to their propagation. Many Lorentz Invariance Violation (LIV) theories predict a dilation of the expected horizon from which UHECRs…
I discuss the shape of the high energy end of the spectrum of particles arising from diffusive shock acceleration in the presence of (i) additional diffusive escape from the accelerator, (ii) continuous energy losses, (iii) energy changes…
We consider the advantages of and the problems associated with hypotheses to explain the origin of ulthrahigh energy cosmic rays (UHECR: E > 10 EeV) and the "trans GZK" cosmic rays (TGZK: E > 100 EeV), both through "old physics"…
The astrophysical engines that power ultra-high-energy cosmic rays (UHECRs) remain to date unknown. Since the propagation horizon of UHECRs is limited to the local, anisotropic Universe, the distribution of UHECR arrival directions should…
Large-scale accretion shocks around massive clusters of galaxies, generically expected in the cold dark matter scenario of cosmological structure formation, are shown to be plausible sources of the observed ultrahigh energy cosmic rays…
We discuss the basic difficulties in understanding the origin of the highest energy particles in the Universe - the ultrahigh energy cosmic rays (UHECR). It is difficult to imagine the sources they are accelerated in. Because of the strong…
The effects of classical gravitational radiation in models with large extra dimensions are investigated for ultra high energy cosmic rays (CRs). The cross sections are implemented into a simulation package (SENECA) for high energy hadron…
We explore particle physics beyond accelerator energies, motivated by questions exposed in astroparticle physics observations: 1) Are there reasonable modifications to the standard extrapolations of LHC-tuned hadronic interaction models, so…
The status of solutions to the ultra-high energy cosmic ray puzzle that involve particle physics beyond the standard model is reviewed. Signatures and experimental constraints are discussed for most proposals like the Z burst model and…
In this paper, prepared for the Physics in Collisions 2008 Conference, the most recent results on UHECRs from earth-based observatories are exposed and reviewed.
In this talk I discuss the interplay between collider physics and four topics of astro-particle physics: neutrino oscillations, electroweak baryogenesis, LSP Dark Matter, and ultra-high energy cosmic rays (UHECR). Some astrophysical…
Violations of Lorentz symmetry are typically associated with modifications of one-particle dispersion relations. The physical effects of such modifications in particle collisions often grow with energy, so that ultrahigh-energy cosmic rays…
Selected applications of perturbative Quantumchromodynamics (QCD) to predictions of the Standard Model for processes at high energy colliders are reviewed with emphasis on past successes and future problems. This is a personal retrospective…
Recent results from the LHC experiments, both for the Higgs mass measurement and the direct search for supersymmetric (SUSY) particles, might indicate that the SUSY breaking scale is much higher than the electroweak scale. Although it is…
The existence of cosmic ray particles up to the ultra-high energy limit (> 10^20 eV) is now beyond any doubt. The detection of cosmic particles with such energies imposes a challenge for the comprehension of their sources and nature. On one…
We study about ultra-high-energy cosmic rays (UHECRs) from transient sources, propagating in the Galactic and intergalactic space. Based on the recent observational results, we also estimate upper and lower bounds on the rate of transient…
The current status of Ultra High Energy Cosmic Rays (UHECR) is reviewed, with emphasis given to theoretical interpretation of the observed events. The galactic and extragalactic origin, in case of astrophysical sources of UHE particles,…
Interactions of ultra-high-energy cosmic rays with background photons set a limit to the distance cosmic rays reaching us above a certain energy can originate from, making measurements of their fluxes insensitive to properties of sources at…
Unparticles from hidden conformal sectors provide qualitatively new possibilities for physics beyond the standard model. In the theoretical framework of minimal models, we clarify the relation between energy scales entering various…
Several explanations for the existence of Ultra High Energy Cosmic Rays (UHECR) invoke the idea that they originate from the decay of massive particles created in the reheating following inflation. It has been suggested that the decay…