Development of 100^{100}Mo-containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

We report recent achievements in the development of scintillating bolometers to search for neutrinoless double-beta decay of $^{100}$Mo. The presented results have been obtained in the framework of the LUMINEU, LUCIFER and EDELWEISS collaborations, and are now part of the R\&D activities towards CUPID (CUORE Update with Particle IDentification), a proposed next-generation double-beta decay experiment based on the CUORE experience. We have developed a technology for the production of large mass ($\sim$1 kg), high optical quality, radiopure zinc and lithium molybdate crystal scintillators (ZnMoO$_4$ and Li$_2$MoO$_4$, respectively) from deeply purified natural and $^{100}$Mo-enriched molybdenum. The procedure is applied for a routine production of enriched crystals. Furthermore, the technology of a single detector module consisting of a large-volume ($\sim 100$~cm$^3$) Zn$^{100}$MoO$_4$ and Li$_2$$^{100}$MoO$_4$ scintillating bolometer has been established, demonstrating performance and radiopurity that are close to satisfy the demands of CUPID. In particular, the FWHM energy resolution of the detectors at 2615 keV --- near the $Q$-value of the double-beta transition of $^{100}$Mo (3034~keV) --- is $\approx$ 4--10~keV. The achieved rejection of $\alpha$-induced dominant background above 2.6~MeV is at the level of more than 99.9\%. The bulk activity of $^{232}$Th ($^{228}$Th) and $^{226}$Ra in the crystals is below 10 $\mu$Bq/kg. Both crystallization and detector technologies favor Li$_2$MoO$_4$, which was selected as a main element for the realization of a CUPID demonstrator (CUPID-0/Mo) with $\sim$7 kg of $^{100}$Mo

Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma

Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson’s chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33–41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ2P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05–5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available

ICAR: endoscopic skull‐base surgery

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Study of Double-beta Decay of 150Nd to the First 0+ Excited Level of 150Sm

Two-neutrino 2β decay of 150Nd to the 0+1 740.5-keV excited level of 150Sm has been investigated by using a highly purified 2.381-kg Nd2O3 sample with the help of ultra-low-background gamma spectrometer with 4 HPGe detectors (≈ 255 cm^3 each) at the Gran Sasso underground laboratory (INFN, Italy). Gamma quanta, expected in cascade after de-excitation of the 0+1 (740.5 keV) excited level of 150Sm, have been observed in the coincidence spectra accumulated over 25947 h. The half-life value has been preliminary estimated as T1/2=[6.9+4.0−1.9(stat)±1.1(syst)]×10^9 y. The data taking is in progress to reduce the statistical error

Aurora experiment: Final results of studies of 116Cd 2β decay with enriched 116CdWO4 crystal scintillators

Final results of studies of 116Cd 2β decay with CdWO4 crystal scintillators, enriched in 116Cd to 82%, are presented. After few years (2011 – 2017) of measurements with radiopure 116CdWO4 scintillators (mass of 1.162 kg) at the Gran Sasso underground laboratory (Italy), the half-life of 116Cd relatively to 2ν2β decay to the ground state of 116Sn was measured with the highest up-to-date accuracy as T1/2=(2.63+0.11−0.12)×10^19 yr. A new limit on 0ν2β decay of 116Cd was set as T1/2≥2.2×10^23 yr at 90% C.L., which is the most stringent to-date restriction for this isotope. Limits for 0ν2β decay with majoron(s) emission, Lorentz-violating 2ν2β decay and 2β transitions to excited states of 116Sn were set at the level of T1/2≥10^20−10^22 yr

Investigation of 2β decay of 116Cd with the help of enriched 116CdWO4 crystal scintillators

Double beta decay of 116Cd has been investigated with the help of radiopure enriched 116CdWO4 crystal scintillators in the experiment Aurora. The half-life of 116Cd relatively to the 2ν2β decay of 116Cd to the ground level of 116Sn is measured with the highest up-to-date accuracy as T1/2 = [2.69 ± 0.02 (stat.) ± 0.14 (syst.)] × 10^19 yr. A new improved limit on the 0ν2β decay of 116Cd to the ground state of 116Sn is set as T1/2 ≥ 2.4 × 10^23 yr at 90% C.L., that corresponds to the effective Majorana neutrino mass limit in the range 〈mν〉 ≤ (1.1 − 1.6) eV, depending on the nuclear matrix elements used in the estimations. New improved limits on other 2β processes in 116Cd (decays with majoron emission, transitions to excited levels of 116Sn) were set at the level of T1/2 ≥ 10^21 − 10^22 yr

Investigation of double beta decay of 116Cd with the help of enriched 116CdWO4 crystal scintillators

An experiment to search for 2β processes in 116Cd with the help of enriched (to 82%) cadmium tungstate crystal scintillators is in progress at the Gran Sasso National Laboratory of the INFN (LNGS, Italy). After 11074 h of data taking in the last configuration, the preliminary estimate for the half-life of 116Cd relatively to 2ν2β decay is T1/2 = [2.52 ± 0.02(stat.) ± 0.14(syst.)] × 10^19 yr. By using the data of previous stages of the experiment with a similar level of background (≈ 0.1 counts/(keV kg yr) in the energy interval 2.7 – 2.9 MeV; the total time of measurements is 19770 h) we have obtained a new limit on the 0ν2β decay of 116Cd to the ground state of 116Sn: T1/2 ≥ 1.9 × 10^23 yr at 90% C.L. New limits on different 2β processes in 116Cd (decays with majorons, transitions to the excited levels) are obtained on the level of T1/2 ≥ 10^20 – 10^22 yr