The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of 130 Te with an array of 988 TeO 2 bolometers operating at temperatures around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the 130 Te decay half-life of 9 × 10 25 years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10 −2 counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of 130 Te is expected.

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We report on the measurement of the twoneutrino double-beta decay half-life of 130 Te with the CUORE-0 detector. From an exposure of 33.4 kg year of TeO 2 , the half-life is determined to be T 2ν 1/2 = [8.2 ± 0.2 (stat.) ± 0.6 (syst.)] × 10 20 year. This result is obtained after a detailed reconstruction of the sources responsible for the CUORE-0 counting rate, with a specific study of those contributing to the 130 Te neutrinoless double-beta decay region of interest.

Neutrinoless double-beta (0νββ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0νββ decay of 130 Te using an array of 988 TeO 2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of 130 Te and have an average energy resolution of 5 keV; the projected 0νββ decay half-life sensitivity after five years of live time is 1.6 × 10 26 y at 1σ (9.5 × 10 25 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40-100 meV (50-130 meV). In this paper we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.

We describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0νββ) decay in 130 Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0νββ decay search in its own right and functions as a platform to further develop the analysis tools and procedures to be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0νββ search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0νββ decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0νββ decay half-life limits previously reported for CUORE-0, T 0ν 1/2 > 2.7 × 10 24 yr, and in combination with the Cuoricino limit, T 0ν 1/2 > 4.0 × 10 24 yr.

The R&D activity performed during the last years proved the potential of ZnSe scintillating bolometers to the search for neutrino-less double beta decay, motivating the realization of the first large-mass experiment based on this technology: CUPID-0. The isotopic enrichment in Se, the ZnSe crystals growth, as well as the light detectors production have been accomplished, and the experiment is now in construction at Laboratori Nazionali del Gran Sasso (Italy). In this paper we present the results obtained testing the first three ZnSe crystals operated as scintillating bolometers, and we prove that their performance in terms of energy resolution, background rejection capability and intrinsic radio-purity complies with the requirements of CUPID-0.

Galaxy hierarchical formation theories, numerical simulations, the discovery of the Sagittarius Dwarf Elliptical Galaxy (SagDEG) in 1994 and more recent investigations suggest that the dark halo of the Milky Way can have a rich phenomenology containing non thermalized substructures. In the present preliminary study, we investigate the case of the SagDEG (the best known satellite galaxy in the Milky Way crossing the solar neighbourhood) analyzing the consequences of its dark matter stream contribution to the galactic halo on the basis of the DAMA/NaI annual modulation data. The present analysis is restricted to some WIMP candidates and to some of the astrophysical, nuclear and particle Physics scenarios. Other candidates such as e.g. the light bosonic ones, we discussed elsewhere, and other non thermalized substructures are not yet addressed here.

CUPID-0 is the first pilot experiment of CUPID, a next-generation project for the measurement of neutrinoless double beta decay (0νDBD) with scintillating bolometers. The detector, consisting of 24 enriched and 2 natural ZnSe crystals, has been taking data at Laboratori Nazionali del Gran Sasso from June 2017 to December 2018, collecting a 82 Se exposure of 5.29 kg×yr. In this paper we present the phase-I results in the search for 0νDBD. We demonstrate that the technology implemented by CUPID-0 allows us to reach the lowest background for calorimetric experiments: (3.5 +1.0 −0.9 ) × 10 −3 counts/(keV kg yr). Monitoring 3.88×10 25 82 Se nuclei×yr we reach a 90% credible interval median sensitivity of T 0ν 1/2 > 5.0 × 10 24 yr and set the most stringent limit on the half-life of 82 Se 0νDBD: T 0ν 1/2 > 3.5 × 10 24 yr (90% credible interval), corresponding to m ββ < (311-638) meV depending on the nuclear matrix element calculations.Nowadays, neutrinoless double beta decay (0νDBD) is considered one of the most sensitive probes for Physics Beyond the Standard Model. This hypothetical nuclear transition foresees the simultaneous decay of two neutrons into protons and electrons without the emission of neutrinos [1]. Its detection would prove the nonconservation of the total lepton number, setting an important milestone for leptogenesis and baryogenesis theories [2]. The observation of 0νDBD would give precious insights also in Particle Physics, as this transition can occur only if neutrinos coincide with their own antiparticles, according to the Majorana hypothesis. As a consequence, its detection would allow to establish the fundamental nature of these particles [3]. Furthermore, if the mechanism at the basis of 0νDBD is the exchange of light Majorana neutrinos, the half-life of the transition (T 0ν 1/2 ) would scale as T 0ν 1/2 ∝ m −2 ββ , where the parameter m ββ (effective Majorana neutrino mass) is a superimposition of the neutrino mass eigenvalues m i weighted by the elements of the neutrino mixing matrix (U ei ): m ββ =| i U 2 ei m i | [4]. Thus, a measurement of T 0ν 1/2 would also allow to constrain the absolute mass scale of neutrinos.The increasing interest in the search for 0νDBD motivated a huge international effort in the development of several technologies [5-9] to study some of the candidate isotopes: elements with even atomic number and even neutron number, for which the single beta decay is strongly forbidden by energy conservation law. These experiments are now envisioning next-generation detectors to probe half-lives exceeding 10 27 yr and, thus, the whole range of the inverted hierarchy region of neutrino masses, whose lower bound is at m ββ ∼10 meV. The main handles to improve the sensitivity are the detector exposure, the background in the region of interest and the energy resolution [10]. To ensure a competitive discovery potential, next-generation detectors will need more than 10 27 emitters (hundreds of kg of source), a background as close as possible to zero in 5-10 years of data-taking, and a...