In this paper, we will discuss the prospects of deducing the proton-air cross section from fluorescence telescope measurements of extensive air showers. As it is not possible to observe the point of first interaction X1 directly, other observables closely linked to X1 must be inferred from the longitudinal profiles. This introduces a dependence on the models used to describe the shower developm...

In this paper we introduce the Terzina telescope as a part of NUSES space mission. This aims to detect Ultra High Energy Cosmic Rays (UHECRs) through Cherenkov light emission from extensive air showers (EAS) that they create in Earth's atmosphere. The photons are aligned along shower axis inside about $\sim 0.2-1^{\circ}$, so become detectable by when it points towards limb. A sun-synchronous o...

Cosmic ray air showers have been known for over 30 years to emit pulsed radio emission in the frequency range from a few to a few hundred MHz, an effect that offers great opportunities for the study of extensive air showers with upcoming fully digital “software radio telescopes” such as LOFAR and the enhancement of particle detector arrays such as KASCADE Grande or the Pierre Auger Observatory....

The normalization constant of the lateral distribution function (LDF) of an extensive air shower is a monotonous (almost linear) increasing function of the energy of the primary. Therefore, the interpolated signal at some fixed distance from the core can be calibrated to estimate the energy of the shower. There is, somehow surprisingly, a reconstructed optimal distance, ropt, at which the effec...

We present a new method for the reconstruction of the longitudinal profile of extensive air showers induced by ultra-high energy cosmic rays. In contrast to the typically considered shower size profile, this method employs directly the ionization energy deposit of the shower particles in the atmosphere. Due to universality of the energy spectra of electrons and positrons, both fluorescence and ...

Fluctuations in the muon content of extensive air showers are anticorrelated to fluctuations energy taken by neutral pions which emerge from first interaction cosmic ray atmosphere. We show that high-energy tail pion spectrum produced proton-air can be constrained, within uncertainties present experiments, through analysis shower-to-shower distribution showers, $P({N}_{\ensuremath{\mu}})$.

The influence of non-linear interaction effects on the characteristics of hadronic collisions and on the development of extensive air showers (EAS) is investigated. Hadronic interactions are treated phenomenologically in the framework of Gribov’s Reggeon approach with non-linear corrections being described by enhanced (Pomeron-Pomeron interaction) diagrams. A re-summation algorithm for higher o...