No abstract

“HADRON-55” with scintillation detectors and ionization calorimeters is used for studies in high-energy gamma-astronomy and cosmic ray physics. The “HADRON-55” consists of two parts - the upper gamma block and the lower hadron block. The gamma block absorbs and detects the electron-photon components of cosmic rays, while hadrons are not absorbed when they pass through the gamma block and begins to form particles in the hadron block. Project's main idea is to select events where there is the interaction in gamma block and no interaction in hadron block. Analysis of experiments results on “HADRON-55” accounts for ∼ 6% of such events. The peripheral part of “HADRON-55” consists of 8 scintillation detectors placed in 2 circles with radii of 40 and 100 m. Over 4 years, more than 120,000 events with high energy of 1015 eV were detected.

Phenomena have been observed in mountain high-energy cosmic-ray experiments, namely, a delayed absorption of high-energy cascades initiated by cosmic-ray hadrons in a lead absorber at E0≳ 1014 eV (so-called long-flying component), a coplanarity of most energetic particles in the central region of γ-ray−hadron superfamilies, and the so-called Tien Shan effect in EAS cores at E0≳ 1016 eV (s>5 TeV). These effects are not described by theoretical models. The coplanarity is explained by the process of coplanar generation of most energetic secondary particles in interactions of superhigh-energy hadrons with the nuclei of air atoms. The other two phenomena are possibly explained with a high cross section for fragmentation-region charmed-hadron generation. To investigate these phenomena, a cosmic-ray detector array, including a very thick ionization calorimeter, is being upgraded to study EAS cores.

Over a long period of time at Tien Shan high-altitude cosmic rays station, located at the height of 3340 m above the sea level, an experiment of studying cosmic radiation hadrons in the field of energy E ≥ 10 13 eV has been carried out. The experimental data were received from complex units «Hadron-9» and «Hadron-44», consisting of ionizing calorimeters, X-ray emulsion chambers and targets of carbon and iron. This work analyzes the most probable mechanisms of the production of leading π 0-mesons. It was shown that major contribution to the generation of leading neutral mesons is made by the process of non-elastic recharging of an incident pion.