連続空気シャワーの到来方向について

LAAS group (LAAS グループ

A study of a phenomena deviated from random feature in EAS energy around 100TeV with new Kinki Array

[Abstract]An EAS observation system was rebuilt in July 1998 at Kinki University which consists of seven 0.25m2 plastic scintillators with fast PMTs. The system works well to detect EASs energy around 100TeV at sea level. In the observation of more than 103 hours, the detector records some phenomenae deviated from average feature in triggering rate, which means each series of the events has extremely small expected frequency in short term data acquisition period. For number of total events this set of consequtive events with upper limit of significant level of 3.6 × 10-2 was found. Although this is not strong evidence deviating from random Poisson distribution, but it has a value of 5σ from average rate. The new Kinki Array is reported briefly and this phenomena is also reported in detail