Hadronic interactions at energies around103TeV inferred from the large-scale emulsion-chamber experiment at Mt. Fuji

Abstract

Details of experimental results, obtained with large-scale emulsion chambers at Mt. Fuji (3776 m above sea level), are presented. The experimental data, which is sensitive to hadronic interactions at energies around ${10}^3$ TeV, is compared with Monte Carlo simulations based on various assumed interaction models and primary particles. The results may be briefly summarized as follows. (1) Scaling in the fragmentation region can be valid up to at least ${10}^3$ TeV only if the primary particles are mixed with significant amounts of heavy nuclei at energies over ${10}^{14}$ eV. (2) Cross sections should continue to increase with energy up to ${10}^3$ TeV, at least, at almost the same rate as that obtained at lower energies. (3) There exists some evidence to indicate remarkable production of particles or jets with high $P_t$ of several GeV/c at energies around ${10}^3$ TeV. (4) Hadron-to-$\gamma$-ray ratios in the observed family events remain almost within the scope of simulation prediction. Other interesting characteristics of family events are also discussed.