Related papers: Identifying String Relics at AUGER?
Over the last decades, radio detection of air showers has been established as a detection technique for ultra-high-energy cosmic-rays impinging on the Earth's atmosphere with energies far beyond LHC energies. Today's second-generation of…
Hadronic interaction models at cosmic ray (CR) energies are inherently uncertain due to the lack of a fundamental theoretical description of soft hadronic and nuclear interactions and the large extrapolation required from collider energies…
The origin and nature of ultra high energy cosmic rays remains being a mystery. However, great progress has been made in recent years due to the observations performed by the Pierre Auger Observatory and Telescope Array. In particular, it…
The shape of the longitudinal development of the showers generated in the atmosphere by very high energy cosmic ray particles encodes information about the mass composition of the flux, and about the properties of hadronic interactions that…
Radio Cherenkov emission underlines detection of high energy particles via a signal growing like the particle-energy-squared. Cosmic ray-induced electromagnetic showers are a primary application. While many studies have treated the…
In order to examine a muon excess observed by the Pierre Auger Observatory, detailed Monte Carlo simulations were carried out for primary protons, iron nuclei and strangelets (hypothetical stable lumps of strange quark matter). We obtained…
The description of high-energy hadronic interactions plays an important role in the (astrophysical) interpretation of air shower data. The parameter space important for the development of air showers (energy and kinematical range) extends…
Ultra-high-energy cosmic rays (UHECR), of energy >10 EeV, arrive at the Earth regularly, but their sources, acceleration mechanisms, details of propagation through the universe, and particle composition remain mysteries. In addition, their…
Nearly 50 years ago, the first radio signals from cosmic ray air showers were detected. After many successful studies, however, research ceased not even 10 years later. Only a decade ago, the field was revived with the application of…
A Monte-Carlo study to reconstruct energy and mass of cosmic rays with energies above 300 TeV using ground based measurements of the electromagnetic part of showers initiated in the atmosphere is presented. The shower properties determined…
Superstring theory predicts the existence of relic metastable particles whose average lifetime is longer than the age of the universe and which could, in principle, be good dark matter candidates. At the same time, these states would be…
High-energy cosmic rays impinging onto the atmosphere of the Earth initiate extensive air showers. With the LOFAR radio telescope and the Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory radio emission from air showers…
It has been suggested that the characteristic energy of string models may be considerably lower than the observed Planck mass. In such schemes, the unification of interactions takes place around the string scale, perhaps as low as a few…
The bulk of air showers initiated by very high energy cosmic rays exhibits a longitudinal development in depth with a single well-defined shower maximum. However, a small fraction of showers has a profile that differs considerably from this…
In this article I review the main theoretical problems that are posed by the highest energy end of the observed cosmic ray spectrum, stressing the importance of establishing their composition in order to decide between proposed scenarios. I…
The field of ultra-high energy cosmic rays made a lot of progresses last years with large area experiments such as the Pierre Auger Observatory, HiRes and the Telescope Array. A suppression of the cosmic ray flux at energies above…
A re-examination of the atmospheric cascade profile of the highest energy cosmic ray is presented. The study includes air-shower simulations considering different cross sections, particle multiplicity and variation of the…
The radio technique for the detection of cosmic particles has seen a major revival in recent years. New and planned experiments in the lab and the field, such as GLUE, Anita, LUNASKA, Codalema, LOPES as well as sophisticated Monte Carlo…
It was recently proposed that predictions of Lorentz-breaking space-time foam models from string theory may be compatible with the suggestion of light-speed variation from gamma-ray burst studies. Our analysis of foam-modified kinematics…
The fluorescence technique has been successfully used to detect ultrahigh energy cosmic rays by indirect measurements. The underlying idea is that the number of charged particles in the atmospheric shower, i.e, its longitudinal profile, can…