No Arabic abstract
High purity TeO2 crystals are produced to be used for the search for the neutrinoless double beta decay of 130Te. Dedicated production lines for raw material synthesis, crystal growth and surface processing were built compliant with radio-purity constraints specific to rare event physics experiments. High sensitivity measurements of radio-isotope concentrations in raw materials, reactants, consumables, ancillaries and intermediary products used for TeO2 crystals production are reported. Production and certification protocols are presented and resulting ready-to-use TeO2 crystals are described.
High purity Zinc Selenide (ZnSe) crystals are produced starting from elemental Zn and Se to be used for the search of the neutrinoless double beta decay (0{ u}DBD) of 82Se. In order to increase the number of emitting nuclides, enriched 82Se is used. Dedicated production lines for the synthesis and conditioning of the Zn82Se powder in order to make it suitable for crystal growth were assembled compliant with radio-purity constraints specific to rare event physics experiments. Besides routine check of impurities concentration, high sensitivity measurements are made for radio-isotope concentrations in raw materials, reactants, consumables, ancillaries and intermediary products used for ZnSe crystals production. Indications are given on the crystals perfection and how it is achieved. Since very expensive isotopically enriched material (82Se) is used, a special attention is given for acquiring the maximum yield in the mass balance of all production stages. Production and certification protocols are presented and resulting ready-to-use Zn82Se crystals are described.
We propose a novel detection concept for neutrinoless double-beta decay searches. This concept is based on a Time Projection Chamber (TPC) filled with high-pressure gaseous xenon, and with separated-function capabilities for calorimetry and tracking. Thanks to its excellent energy resolution, together with its powerful background rejection provided by the distinct double-beta decay topological signature, the design discussed in this Letter Of Intent promises to be competitive and possibly out-perform existing proposals for next-generation neutrinoless double-beta decay experiments. We discuss the detection principles, design specifications, physics potential and R&D plans to construct a detector with 100 kg fiducial mass in the double-beta decay emitting isotope Xe(136), to be installed in the Canfranc Underground Laboratory.
This paper presents a review of the search for neutrinoless double beta decay of $^{76}$Ge with emphasis on the recent results of the GERDA experiment. It includes an appraisal of fifty years of research on this topic as well as an outlook.
The NEMO-3 experiment at the Modane Underground Laboratory has investigated the double-$beta$ decay of $^{48}{rm Ca}$. Using $5.25$ yr of data recorded with a $6.99,{rm g}$ sample of $^{48}{rm Ca}$, approximately $150$ double-$beta$ decay candidate events have been selected with a signal-to-background ratio greater than $3$. The half-life for the two-neutrino double-$beta$ decay of $^{48}{rm Ca}$ has been measured to be $T^{2 u}_{1/2},=,[6.4, ^{+0.7}_{-0.6}{rm (stat.)} , ^{+1.2}_{-0.9}{rm (syst.)}] times 10^{19},{rm yr}$. A search for neutrinoless double-$beta$ decay of $^{48}{rm Ca}$ yields a null result and a corresponding lower limit on the half-life is found to be $T^{0 u}_{1/2} > 2.0 times 10^{22},{rm yr}$ at $90%$ confidence level, translating into an upper limit on the effective Majorana neutrino mass of $< m_{betabeta} > < 6.0 - 26$ ${rm eV}$, with the range reflecting different nuclear matrix element calculations. Limits are also set on models involving Majoron emission and right-handed currents.
The CUPID-Mo experiment is searching for neutrinoless double beta decay in $^{100}$Mo, evaluating the technology of cryogenic scintillating Li$_{2}^{100}$MoO$_4$ detectors for CUPID (CUORE Upgrade with Particle ID). CUPID-Mo detectors feature background suppression using a dual-readout scheme with Li$_{2}$MoO$_4$ crystals complemented by Ge bolometers for light detection. The detection of both heat and scintillation light signals allows the efficient discrimination of $alpha$ from $gamma$&$beta$ events. In this proceedings, we discuss results from the first 2 months of data taking in spring 2019. In addition to an excellent bolometric performance of 6.7$,$keV (FWHM) at 2615$,$keV and an $alpha$ separation of better than 99.9% for all detectors, we report on bulk radiopurity for Th and U. Finally, we interpret the accumulated physics data in terms of a limit of $T_{1/2}^{0 u},> 3times10^{23},$yr for $^{100}$Mo and discuss the sensitivity of CUPID-Mo until the expected end of physics data taking in early 2020.