Experimental observations of extensive air showers have revealed an excess the muon content with respect to their theoretical simulations, which we refer as puzzle. This puzzle hampers a precise determination ultra-high-energy cosmic ray mass composition. We investigate potential producing states dense quark-gluon matter (which call fireballs) resolve quantified data from Pierre Auger Observato...

Frequency distributions of local muon densities in high-energy extensive air-showers (EAS) are presented as signature of the primary cosmic ray energy spectrum in the knee region. Together with the gross shower variables like shower core position, angle of incidence, and the shower sizes, the KASCADE experiment is able to measure local muon densities for two different muon energy thresholds. Th...

The “knee” of cosmic ray spectra reflects the maximum energy accelerated by galactic sources or limit to ability galaxy bind rays. measuring individual is a crucial tool ascertain origin knee. However, and identifying primary nuclei are foundation components. Extensive Air Shower rays in knee region simulated via CORSIKA software. resolution for different secondary components (include electron,...

In models with large extra dimensions, particle collisions with center-of-mass energy larger than the fundamental gravitational scale can generate nonperturbative gravitational objects. Since cosmic rays have been observed with energies above 108 TeV, gravitational effects in the TeV energy range can, in principle, be observed by ultrahigh energy cosmic ray detectors. We consider the interactio...

A simulation study of the energy released in air due to the development of an extensive air shower has been carried out using the CORSIKA code. The contributions to the energy release from different particle species and energies as well as the typical particle densities are investigated. Special care is taken of particles falling below the energy threshold of the simulation which contribute abo...

We present LOFAR measurements of radio emission from extensive air showers. We find that this emission is strongly polarized, with a median degree of polarization of nearly 99%, and that the angle between the polarization direction of the electric field and the Lorentz force acting on the particles, depends on the observer location in the shower plane. This can be understood as a superposition ...

We revisit and extend the analysis supporting a 60 year-old suggestion that cosmic rays air showers resulting from primary particles with energies above 10 eV should be straightforward to detect with radar ranging techniques, where the radar echoes are produced by scattering from the column of ionized air produced by the shower. The idea has remained curiously untested since it was proposed, bu...

Results of experiments investigating air showers in the energy region of the knee are summarized. The all-particle energy spectrum, the mean logarithmic mass, and the average depth of the shower maximum will be discussed. Spectra for groups of elements from air shower data are compared to results from direct measurements.

In this report a summary of recent developments in the fields of high-energy nuclear interactions (HE 1) and air shower phenomenology (HE 2) is presented. New results from accelerator and cosmic-ray experiments and the progress in the theoretical understanding and simulation are reviewed and their impact on air shower analysis is discussed.