Neutral particles in hadron-nuclear interactions at ultrahigh energies

Six inelastic interactions of primary protons and α-particles with carbon atom nuclei at E0>20 TeV incident particle energies are investigated in detail during balloon experiments conducted by means of X-ray emulsion chambers with target unit. Conclusions are made that η0 mesons are essentially generated alongside with π0 mesons in inelastic interactions of protons and α particle with E0=100 TeV mean energy with carbon atom nuclei. Transverse momenta of η0 mesons are on an average by 2 times higher, than longitudinal momenta of π0 mesons. Mean energy of η0 mesons is several times higher than mean energy of π0 mesons