Search

CUPID-0 is the first large mass neutrino-less double beta decay ( 0 ν β β ) experiment based on cryogenic calorimeters with dual read-out of light and heat for background rejection. The detector assembly, consisting of 26 ZnSe crystals, 2 natural and 24 enriched at 95% in 82Se, all coupled with bolometric light detectors, has been constructed respecting very strict protocols and procedures, from the material selection during crystal growth to the new and innovative detector framework, in the attempt to achieve the best performance of the array. The successful construction of the detector lead to promising preliminary results, here presented. The array is in fact taking data underground at LNGS (Italy) since March 2017 and the particle identification, enabled by the light read-out, provides an unprecedented background level, for cryogenic calorimeters, of only 3.2 counts keV − 1 t − 1 yr − 1 in the region of interest of the 0 ν β β search for 82Se, namely around 3 MeV.

International audience; Bolometric detectors are excellent devices for the investigation of neutrinoless double-beta decay (). The observation of such decay would demonstrate the violation of lepton number, and at the same time, it would necessarily imply that neutrinos are Majorana particles. The sensitivity of cryogenic detectors based on TeO is strongly limited by the -background in the region of interest for the 0 of Te. It has been demonstrated that particle identification in TeO bolometers is possible, measuring the Cherenkov light produced by particle interactions. However, the discrimination efficiency is low, and an event-by-event identification with NTD-based light detectors has to be demonstrated. We will discuss the performance of a highly sensitive light detector exploiting the Neganov-Luke effect for signal amplification. The detector, being operated with NTD thermistor and coupled to a 750 g TeO crystal, shows the ability for an event-by-event identification of electron/gamma and particles. The obtained results demonstrate the possibility to enhance the sensitivity of TeO-based 0 experiment to an unprecedented level.

In the field of fundamental particle physics, the neutrino has become more and more important in the last few years, since the discovery of its mass. In particular, the ultimate nature of the neutrino (if it is a Dirac or a Majorana particle) plays a crucial role not only in neutrino physics, but also in the overall framework of fundamental particle interactions and in cosmology. The only way to disentangle its ultimate nature is to search for the neutrinoless double beta decay. The idea of LUCIFER is to combine the bolometric technique proposed for the CUORE experiment with the bolometric light detection technique used in cryogenic dark matter experiments. The bolometric technique allows an extremely good energy resolution while its combination with the scintillation detection offers an ultimate tool for background rejection. The goal of LUCIFER is not only to build a background-free small-scale experiment but also to directly prove the potentiality of this technique. Preliminary tests on several detectors containing different interesting DBD emitters have clearly demonstrated the excellent background rejection capabilities that arise from the simultaneous, independent, double readout of heat and scintillation light. © 2013 J. W. Beeman et al.