New ordering principle for the classical statistical analysis of Poisson processes with background

Inspired by the recent proposal by Feldman and Cousins of a “unified approach to the classical statistical analysis of small signals” based on a choice of ordering in Neyman’s construction of classical confidence intervals, I propose a new ordering principle for the classical statistical analysis of Poisson processes with a background which minimizes the effect on the resulting confidence intervals of the observation of fewer background events than expected. The new ordering principle is applied to the calculation of the confidence region implied by the recent null result of the KARMEN neutrino oscillation experiment.