Patterns on the Fish Skins Induced by Anisotropy in Diffusion (Interfaces, Pulses and Waves in Nonlinear Dissipative Systems : RIMS Project 2000 "Reaction-diffusion systems : theory and applications")

The EURECA (European Underground Rare Event Calorimeter Array) project is aimed at searching for dark matter particles using cryogenic bolometers. The proponents of the present project have decided to pool their strengths and expertise to build a facility to house up to 1000 kg of detectors, EURECA, consisting in the first instance of germanium and CaWO 4 crystals. The shielding will be provided through a large water tank in which the cryostat with detectors will be immersed. The EURECA infrastructure will be an essential tool for the community interested in using cryogenic detectors for dark matter searches. Beyond European detectors, it will be designed to host other types of similar cryogenic detectors, requiring millikelvin operating temperatures. In particular, this includes the germanium detectors currently in use by the SuperCDMS team, following the current collaborative work performed by the EURECA and SuperCDMS collaborations. EURECA will have two stages. The first phase aims at a sensitivity of 3 . 10 −10  pb and will involve building the infrastructure, cryostat and shielding, and operating 150 kg of detectors. The second phase will be completed with 850 kg of additional detectors, the relative weight between the different detectors being decided by the collaboration according to the physics reach. A sensitivity of 2 . 10 −11 pb is aimed for at the second stage. EURECA will ideally benefit from the planned extension of the deepest underground laboratory in Europe  – LSM. With a site-independent design, it can also be hosted in other locations at similar or deeper sites such as SNOLAB

LUMINEU: a search for neutrinoless double beta decay based on ZnMoO 4 scintillating bolometers

The LUMINEU is designed to investigate the possibility to search for neutrinoless double beta decay in 100Mo by means of a large array of scintillating bolometers based on ZnMoO4 crystals enriched in 100Mo. High energy resolution and relatively fast detectors, which are able to measure both the light and the heat generated upon the interaction of a particle in a crystal, are very promising for the recognition and rejection of background events. We present the LUMINEU concepts and the experimental results achieved aboveground and underground with large-mass natural and enriched crystals. The measured energy resolution, the α/β discrimination power and the radioactive internal contamination are all within the specifications for the projected final LUMINEU sensitivity. Simulations and preliminary results confirm that the LUMINEU technology can reach zero background in the region of interest (around 3 MeV) with exposures of the order of hundreds kgXyears, setting the bases for a next generation 0v2β decay experiment capable to explore the inverted hierarchy region of the neutrino mass pattern