STATISTICAL TECHNIQUES DEVELOPED BY THE UKDMC TO CALCULATE THE 90-PERCENT CL UPPER LIMIT OF THE WIMP COMPONENT OF THE GALACTIC DARK-MATTER

This paper outlines statistical techniques developed by the UK Dark Ma tter Collaboration to convert the resultant energy spectra from NaI cr ystal scintillation detectors to a 90% confidence level upper limit to the rate of the hypothetical weakly interacting massive dark matter p article, the WIMP. In simple counting systems a chi-square surface min imisation technique is used, the 90% c.l. arising from Monte Carlo sim ulations. In detectors that exhibit electron from nuclear recoil discr imination a comparison between the observed spectrum and that from gam ma and neutron calibrations is performed with chi-square, Kolmogorov-S mirnov and Cramer-von-Mises tests to give the most likely signal, with Monte Carlo simulations again yielding the 90% c.l.