Based on a new approach to the detection of radio transients associated with extensive air showers induced by ultra high energy cosmic rays, the experimental apparatus CODALEMA is in operation, measuring about 1 event per day corresponding to an energy threshold ∼ 5 × 10 eV. Its performance makes possible for the first time the study of radio-signal features on an event-by-event basis. The samp...

The proposed SCORE detector consists of a large array of light collecting modules designed to sample the Cherenkov light front of extensive air showers in order to detect high energy γ-rays. A large spacing of the detector stations makes it possible to cover a huge area with a reasonable effort, thus achieving a good sensitivity up to energies of about a few 10 PeV. In this paper the event reco...

General physics of very high energy hadronic interactions is discussed. Special attention is payed to the contribution of semihard processes to the interaction dynamics and to the role of parton shadowing and parton density saturation. In particular, the implementation of non-linear interaction effects in the QGSJET-II model is discussed in detail. The predictions of the model are compared to s...

The time structure of muons at ground retains valuable information about the longitudinal development of the hadronic component in extensive air showers. Using the signals collected by the surface detector array of the Pierre Auger Observatory it is possible to reconstruct the Muon Production Depth (MPD) distribution. In this work we explore the main features of these reconstructions for zenith...

Ground based experiments as extensive air shower arrays can observe 1÷10 GeV Gamma-Ray Bursts using the ”single particle” technique. The sensitivity to detect a GRB as a function of the burst parameters and the detector characteristics are discussed. The rate of possible observations is evaluated, making reasonable assumptions on the high energy emission, the absorption of gammarays in the inte...

1. Primary cosmic radiation (PCR) of ultrahigh energies (E0 > 4 × 1017 eV) is thought to consist primarily of charged particles, protons, and nuclei of various chemical elements. These charged particles are strongly mixed by the magnetic field of the galaxy and distributed almost isotropically over the celestial sphere. For this reason, it is difficult to find the local sources of PCR. The abov...

Leptoquarks arise naturally in models attempting the unification of the quark and lepton sectors of the standard model of particle physics. Such particles could be produced in the interaction of high energy quasi-horizontal cosmic neutrinos with the atmosphere, via their direct coupling to a quark and a neutrino. The hadronic decay products of the leptoquark, and possibly its leptonic decay pro...

Current Monte Carlo simulations do not provide a good description of the muon component extensive air showers. Many shower experiments report discrepancies between their data and predictions, ranging from TeV scale up to highest energies. In these proceedings, we address seasonal variation multi-muon events observed by NOvA Near Detector (ND). For our studies, use general-purpose code FLUKA tre...

The alignment of the products of very high energy interactions seen in mountain altitude experiments is one of the most puzzling phenomena in cosmic ray physics for quite a long time. The observations of the Pamir and Chacaltaya emulsion chamber groups and by the Tien-Shan extensive air shower experiment, together with a very clear event seen in the Concorde French– Japanese experiment in the s...

In models with substructure in the fermionic sector, excited fermion states are expected. Excited leptons could be produced in the interaction of high energy quasihorizontal cosmic neutrinos with the atmosphere via neutral and charged current processes, νN → ν∗X and νN → l∗X. The hadronic component X, and possibly part of the excited lepton decay products, would originate an extensive air showe...