Related papers: Multiple UHECR Events from Galactic hadron jets
The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 1017eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a…
The mass composition of ultra-high-energy cosmic rays (UHECRs) is usually inferred from the depth of the shower maximum ($X_{\rm{max}}$) of cosmic-ray showers, which is only ambiguously determined by modern hadronic interaction models. We…
Top-down models for the origin of ultra high energy cosmic rays (UHECR's) propose that these events are the decay products of relic superheavy metastable particles, usually called $X$ particles. These particles can be produced in the…
Ultra High Energy Cosmic Rays (UHECR) can be a signal from very early (post-inflationary) Universe. At this cosmological epoch Topological Defects (TD) and long-lived suprheavy (SH) particles are expected to be naturally and effectively…
Ultra High Cosmic Rays (UHECR) Astronomy may be correlated to a primary parental Neutrino Astronomy: indeed any far BL Lac Jet or GRB, sources of UHECR, located at cosmic edges, may send its signal, overcoming the severe GZK cut-off, by…
Measurements of proton and nuclear collisions at the Large Hadron Collider at nucleon-nucleon c.m. energies up to $\sqrt{s_{NN}}=$ 13 TeV, have improved our understanding of hadronic interactions at the highest energies reached in…
Having previously argued that binary neutron star mergers are the principle source of ultrahigh energy cosmic rays~\citep{fBNS-prl25}, we exploit here the highly constrained initial conditions to make quantitative predictions for the cutoff…
Detecting neutrinos and photons is crucial to identifying the sources of ultrahigh-energy cosmic rays (UHECRs), especially for transient sources. We focus on ultrahigh-energy gamma-ray emission from transient sources such as gamma-ray…
Ultra-high energy cosmic rays (UHECRs) are particles, likely protons and/or nuclei, with energies up to $10^{20}$ eV that are observed through the giant air showers they produce in the atmosphere. These particles carry the information on…
We explore the potential of a future, ultra-high energy cosmic ray (UHECR) experiment, that is able to overcome the limitation of low statistics, to detect anisotropy in the arrival directions of UHECRs. We concentrate on the lower energy…
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…
Large-scale accretion shocks around massive clusters of galaxies, generically expected in hierarchical scenarios of cosmological structure formation, are shown to be potential sources of the observed ultrahigh energy cosmic rays (UHECRs) by…
The origin of ultra-high-energy cosmic rays (UHECRs) remains an open questions in astrophysics. We explore two primary scenarios for the distribution of UHECR sources, assuming that their production rate follows either the cosmic…
We study the anisotropy of Ultra-High Energy Cosmic Ray (UHECR) events collected by the Telescope Array (TA) detector in the first 40 months of operation. Following earlier studies, we examine event sets with energy thresholds of 10 EeV, 40…
The origin of ultra-high energy cosmic rays $($UHECRs$)$ remains a mystery. It has been suggested that UHECRs can be produced by the stochastic acceleration in relativistic jets of gamma-ray bursts $($GRBs$)$ at the early afterglow phase.…
Recent studies suggest that the most energetic cosmic rays, exceeding 100 EeV, may primarily consist of $r$-process nuclei. This highlights binary neutron star mergers and collapsars as promising sources of ultra-high-energy cosmic rays…
For several decades, the origin of ultra-high-energy cosmic rays (UHECRs) has been an unsolved question of high-energy astrophysics. One approach for solving this puzzle is to correlate UHECRs with high-energy neutrinos, since neutrinos are…
The photomeson production in ultra-high-energy cosmic-ray (UHECR) accelerators such as gamma-ray bursts and active galaxies may lead to ultra-high-energy (UHE) gamma-ray emission. We show that generation of UHE pairs in magnetized…
We predict the arrival distribution of UHECRs above $4 \times 10^{19}$ eV with the event number expected by future experiments in the next few years. We perform event simulations with the source model which is adopted in our recent study…
We explore inferences on ultrahigh energy cosmic ray (UHECR) source environments -- constrained by the spectrum and composition of UHECRs and non-observation of extremely high energy neutrinos -- and their implications for the observed high…