LIQUID XENON AS A DARK-MATTER DETECTOR - PROSPECTS FOR NUCLEAR RECOILDISCRIMINATION BY PHOTON TIMING

Two mechanisms lead to liquid xenon scintillation, and are excited dif ferently by incident electrons and by heavy charged nuclei. This could be used to discriminate nuclear recoil events from radioactive backgr ound in a search for hypothetical Galactic dark matter particles. To a chieve low energy threshold a likelihood analysis is proposed using th e time intervals between detected photons. Results are presented of Mo nte Carlo simulations, showing the background rejection achievable as a function of the number of detected photons. Some comments are includ ed on background discrimination by simultaneous measurement of scintil lation and ionization signals.