Cryogenic Underground Observatory For Rare Events Experiment Research Articles

Latest Results from the CUORE Experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first cryogenic experiment searching for 0nu beta beta decay that has been able to reach the one-tonne mass scale. The detector, located at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, consists of an array of 988 {mathrm{TeO}}_{2} crystals arranged in a compact cylindrical structure of 19 towers. CUORE began its first physics data run in 2017 at a base temperature of about 10 mK and in April 2021 released its 3{mathrm{rd}} result of the search for 0nu beta beta , corresponding to a tonne-year of mathrm{TeO}_{2} exposure. This is the largest amount of data ever acquired with a solid state detector and the most sensitive measurement of 0nu beta beta decay in {}^{130}mathrm{Te} ever conducted . We present the current status of CUORE search for 0nu beta beta with the updated statistics of one tonne-yr. We finally give an update of the CUORE background model and the measurement of the {}^{130}mathrm{Te}2nu beta beta decay half-life and decay to excited states of {}^{130}mathrm{Xe}, studies performed using an exposure of 300.7 kg yr.

New results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrino-less double-beta (0[Formula: see text]) decay that has been able to reach the one-ton scale. The detector, located at the Laboratori Nazionali del Gran Sasso in Italy, consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. Following the completion of the detector construction in August 2016, CUORE began its first physics data run in 2017 at a base temperature of about 10 mK. Following multiple optimization campaigns in 2018, CUORE is currently in stable operating mode. In 2019, CUORE released its second result of the search for 0[Formula: see text] corresponding to a TeO2 exposure of 372.5 kg[Formula: see text]⋅[Formula: see text]yr and a median exclusion sensitivity to a 130Te 0[Formula: see text] decay half-life of [Formula: see text] yr. We find no evidence for 0[Formula: see text] decay and set a 90% C.I. Bayesian lower limit of [Formula: see text] yr on the 130Te 0[Formula: see text] decay half-life. We present the current status of CUORE’s search for 0[Formula: see text]. We give an update of the CUORE background model and the measurement of the 130Te two neutrino double-beta (2[Formula: see text]) decay half-life. Eventually, we show the preliminary results on half-life limits from the analysis of 130Te 0[Formula: see text] and 2[Formula: see text] decay to the first 0[Formula: see text] excited state of [Formula: see text]Xe.

Status and results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is a tonne-scale cryogenic experiment located at the Laboratori Nazionali del Gran Sasso that exploits bolometric technique to search for neutrinoless double beta decay [Formula: see text] of [Formula: see text]Te. The detector consists of a segmented array of 988 natural [Formula: see text] cubic crystals arranged in a cylindrical compact structure of 19 towers. The detector construction was completed in August 2016 and data taking started in Spring 2017. In this work, we present a brief description of the bolometric technique for rare events search and the CUORE detector, then we concentrate on the data analysis results. In this respect, we focus on the procedure for data processing and on the first [Formula: see text] results we obtained from a total [Formula: see text] exposure of [Formula: see text]. Next, we illustrate the main background sources and the CUORE background model, from which we obtain the most precise measurement of [Formula: see text]Te [Formula: see text] half-life to date. Finally, we discuss the improvements achieved with 2018 and 2019 detector optimization campaigns and the current perspectives of our experiment.

First results from the CUORE experiment

CUORE (Cryogenic Underground Observatory for Rare Events) is a ton-scale experiment aiming to the search of neutrino-less double beta decay in 130Te with a projected sensitivity on the Majorana effective mass close to the inverted hierarchy region. The CUORE detector consists of a segmented array of 988 TeO2 bolometers, organized in 19 towers and operated at a temperature of about 10 mK thanks to a custom cryogenic system which, besides the uncommon scale, observes several constraints from the radio-purity of the materials to the mechanical decoupling of the cooling systems. The successful commissioning of the CUORE cryogenic system has been completed early in 2016 and represents an outstanding achievement by itself. The installation of the detector proceeded along 2016 followed by the cooldown to base temperature at the beginning of 2017. The CUORE detector is now operational and has been taking science data since Spring 2017. With the first ~3 weeks of collected data, we present here the most stringent constraint on the 130Te half-live for the neutrino-less double beta decay.

Results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta (0νββ) decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. The construction of the experiment and, in particular, the installation of all towers in the cryostat was completed in 2016 and data taking started in 2017. In this conference we present the 0νββ decay results of CUORE from examining a total TeO2 exposure of 86.3 kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/(keV kg yr). Based on these data, CUORE places a lower limit on the 0νββ decay half-life of (90% C.L.). We then discuss the latest updates in the analysis of background and in the evaluation of the half-life of 2νββ decay of 130Te.

The CUORE experiment at LNGS

Since the discovery of neutrino, many of its properties have been studied. The flavor oscillations recently revealed that, contrary to the Standard Model assumptions, neutrinos have a finite mass. Other neutrino characteristics are still to be investigated, such as its Dirac or Majorana nature: experiments are currently searching for a rare phenomenon, the neutrinoless double beta decay (0νββ), whose observation would solve this issue. The Cryogenic Underground Observatory for Rare Events (CUORE) at Gran Sasso National Laboratories focuses on the search of 130Te 0νββ and it is the first ton-scale bolometric experiment ever realized for this purpose. The detector is hosted inside a custom cryostat and consists of 988 TeO2 crystals, operated at a temperature of ∼ 10 mK. The CUORE goals in 5 years of data taking are an energy resolution of 5 keV FWHM and a background level of 0.01 counts/keV/kg/y in the 130Te 0νββ region of interest. This corresponds to a sensitivity on the 130Te 0νββ half life of T1/2 = 9 · 1025 y (90% C.L.) and an upper limit to the effective Majorana mass of 50 − 130 meV. The CUORE commissioning has been recently completed; the experiment has just concluded the pre-operation phase and data taking is currently ongoing.

Commissioning of the 4 K Outer Cryostat for the CUORE Experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is a 1-ton scale bolometric experiment. The CUORE detector is an array of 988 TeO\(_2\) crystals arranged in a cylindrical, compact, and granular structure of 19 towers. These detectors will need a base temperature lower than 10 mK in order to meet the performance specifications. To cool the CUORE detector, a large cryogen free cryostat with five pulse tubes and one custom designed high power dilution refrigerator has been designed. The three vessels that form the outer shell of the CUORE cryostat were produced in 2012 and are now assembled in the Gran Sasso National Laboratories (LNGS). We report here the detailed description of the 4 K outer cryostat for the CUORE experiment together with the results of the validation tests done at the production site in 2012 and of the first commissioning to 4 K at LNGS in 2013.

Physics potential and prospects for the CUORICINO and CUORE experiments

The Cryogenic Underground Observatory for Rare Events (CUORE) experiment projects to construct and operate an array of 1000 cryogenic thermal detectors of TeO 2, of a mass of 760 g each, to investigate rare events physics, in particular, double beta decay and non-baryonic particle dark matter. A first step towards CUORE is CUORICINO, an array of 62 bolometers, currently being installed in the Gran Sasso Laboratory. In this paper we report the physics potential of both stages of the experiment regarding neutrinoless double beta decay of 130Te, WIMP searches and solar axions.