天体物理学と航空宇宙技術

Nuclear Physics: Estimating the Mean Lifetime from Partially Observed Events

Abstract

Jan Saren

In nuclear physics, one important property of particles to identify is their mean lifetime. The arrivals and subsequent radioactive decays (departures) of single radioactive nuclei can be detected by cutting-edge particle detectors. When there is inconsistency between arrivals and departures and only partial observation of departures, problems arise. Experiments in which the arrival rate is set very low to allow for matching of arrivals and departures are inefficient. An estimation technique that works for a wide range of arrival rates is what we propose. An initial estimator and a method for correcting numerical bias are combined in this approach. The method provides accurate estimates regardless of the arrival rate, as demonstrated by examples and simulations based on data on Lutetium isotope 155 alpha decays. The estimation technique makes it possible to make use of all of the data gathered by the particle detector, which has the practical advantage of allowing for more precise estimates and, in some instances, shorter experiments.