Analysis of rare events in heavy-ion experiments

Experiments in both high-and low-energy physics are planned so that physically interesting effects mathematically are rare (or small probability) events, compared to others, whose probabilities are not small. Correspondingly, the purpose of the paper was the development of the formalism for the treatment of rare events, which could be an inevitable alternative to methods requiring too much a priori information about the studied effect, in a situation when such information is absent, but, instead, background information is available, e.g., from calibration measurements. The main topics of the paper were as follows: (1) To what extent are the methods of Poisson time-event streams suitable for the goal declared? (2) What information can be extracted from the calibration measurement that detected zero interesting events? The method described is illustrated by the analysis of data registered in the experiment on the synthesis of element 114.