Air-showers, bursts and high energy families detected by hybrid experiments atMt.Chacaltaya

The hybrid experiment on Mt.Chacaltaya gives informations on various component in the air-showers. We have shown, from the analysis of the hybrid data, that the current interaction models can not describe well the characteristics of air-shower-triggered families by studying a correlation between air-shower size and accompanied family energies. In this paper we study in detail further correlations between air-shower size and burst-size, and those between burst-size and family energy in addition to those between air-shower size and family energy. Air-showers are calculated using CORSIKA simulation code with interaction models of QGSJET and EPOS, and burst-size of the events are calculated based on the simulations using GEANT4 code, taking into consideration the exact structure of the experimental hadron calorimeter. Comparison of the burst-size dependence of the family energy shows that the observed family energy accompanied by the air-showers with larger burst-size is systematically smaller than that expected in the simulated events. The experimental results can not be described simply by changing chemical composition of primary cosmic-rays and this indicates a necessity of some changes in the interaction model.