Seminarium Fizyki Wielkich Energii

The different experiments attempting direct detection of Dark Matter candidates (DM) provides divergent results. DAMA-LIBRA observed the annual modulation in count rate which suggest existence of DM with MDM = O(10 GeV/c2). However, other (mostly l. Xenon detectors) put impressive limits on DM in mass range of 15 GeV/c2 < MDM < 500 GeV/c2. There is still possibility that DM are WIMPs, they are either low mass, MDM < 15 GeV/c2 or very heavy. We propose new DM detectors based on coherent scattering of neutrinos or DM in ancient crystals. Such crystals are available from deepest holes drilled for diverse purposes (depth > 8 km or > 20 km water equivalent). Thus the background due to CR is negligible (with exception of neutrinos). In this new detectors, the target is multi-elemental (up to 10 elements) which provides the signature and improve S/B. We elucidate the principles of paleo-detectors and describe a few promising methods of the signal detection. We also provide the first estimates of sensitivities, which for low mass DM (LM-DM) extends below the current definition of the “neutrino floor”. For example, for MDM = 10 GeV our sensitivity is about thousand fold better than for Ge-based or l. Xenon detectors. The problems of backgrounds will be discussed, including the trade-offs when one try use ice from Antarctica as paleo-detector.