相关论文: On some Implications of (Symmetric) Special Relati…
We present the extent to which anisotropies in the ultrahigh energy neutrino sky can probe the distribution of extreme astrophysical accelerators in the universe. In this talk, we discuss the origin of an anisotropic neutrino sky and show…
Ultra-high energy cosmic rays interacting with the radiation fields in the universe cause electromagnetic cascades resulting in a flux of extragalactic gamma rays, detectable to some 100 GeV. Recent precise measurements of the extragalactic…
Gamma-ray bursts are short-lived, luminous explosions at cosmological distances, thought to originate from relativistic jets launched at the deaths of massive stars. They are among the prime candidates to produce the observed cosmic rays at…
Cosmic-rays with energies exceeding 10^{19} eV are referred to as Ultra High Energy Cosmic Rays (UHECRs). The sources of these particles and their acceleration mechanism are unknown, and for many years have been the issue of much debate.…
The current status of the theory of particle acceleration at relativistic shocks is presented, and a few possible scenarios for ultra-high-energy cosmic ray production at such shocks are briefly discussed.
We make a review of the main nuclear effects that affect neutrino-nucleus cross sections. We discuss how the different models in the literature try to describe these different effects, and thus try to compare between them. We focus on the…
Neutrinos from far away sources annihilating at the Z resonance on relic neutrinos may give origin to the ultrahigh-energy cosmic rays. Here we present predictions of this mechanism with relic neutrinos lighter than 1 eV, which do not…
Scenarios in which the knee of the cosmic ray spectrum depends on the particle rigidities usually predict that the cosmic ray composition becomes heavier above the knee and have associated a change in the spectral slope of each individual…
A fundamental question that can be answered in the next decade is: WHAT IS THE ORIGIN OF THE HIGHEST ENERGY COSMIC PARTICLES? The discovery of the sources of the highest energy cosmic rays will reveal the workings of the most energetic…
Decaying superheavy particles can be produced by Topological Defects or, in case they are quasi-stable, as relics from the early Universe. The decays of these particles can be the sources of observed Ultra High Energy Cosmic Rays ($E \sim…
An analysis of the existing data on the atmospheric neutrino anomaly is presented, focused on the statistical significance that can be attributed to its experimental evidence. Our approach is alternative to the usual analyses in terms of…
The Fermi acceleration model was introduced to describe how cosmic ray particles are accelerated to great speeds by interacting with moving magnetic fields. We identify a new variation of the model where light ions interact with a moving…
In this paper we analyse the effect of the anomalous magnetic moment on the non-relativistic quantum motion of a neutral particle in magnetic and electric fields produced by linear sources of constant current and charge density,…
Coincidence scattering of polarized electrons from nuclei with polarization transfer to outgoing nucleons is studied within the context of relativistic mean field theory. Effects introduced by the dynamical enhancement of the lower…
Recent measurements of cosmic ray electron energy spectra suggest that above 10 GeV there may be deviations from a single power law spectrum. There are hints (ATIC) for a bump occurring between 100 GeV and 1TeV, meaning that there might be…
The understanding of the particle spectra resulting from acceleration in relativistic shocks as they occur in extragalactic sources, is essential for the interpretation of the cosmic ray spectrum above the ankle ($E_p>3\cdot 10^{18}$ eV).…
The origin and nature of ultrahigh-energy cosmic ray events, above the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy, constitute a long-standing, unsolved mistery. Neutrinos are proposed candidates but their standard interactions with matter…
We present a novel approach to search for origins of ultra-high energy cosmic rays. These particles are likely nuclei that initiate extensive air showers in the Earth's atmosphere. In large-area observatories, the particle arrival…
The observation of neutrinos from cosmic accelerators will be revolutionary. High energy neutrinos are closely connected to ultrahigh energy cosmic rays and their sources. Cosmic ray sources are likely to produce neutrinos and the…
The recent discoveries of high-energy cosmic neutrinos and gravitational waves from astrophysical objects have led to the new era of multi-messenger astrophysics. In particular, electromagnetic follow-up observations triggered by these…