Application of quasi-optimal weights to searches of anomalies. Statistical criteria for step-like anomalies in cumulative spectra

摘要

It is demonstrated how the method of quasi-optimal weights can be applied to searches of anomalies in experimental data. As an example, a convenient statistical criterion is derived for step-like anomalies in cumulative p-decay spectra in the direct neutrino mass measurement experiments, It is almost as-powerful as the locally most powerful one and appreciably excels the conventional X~2 and Kolmogorov-Smirnov tests. It is also compared with an ad hoc criterion of «pairwise correlations of neighbours^; the latter is seen to be less powerful even if more sensitive to more general anomalies. As a realistic example, the criteria are applied to the Troitsk-v-mass data.