Abstract
We report the measurement of the two-neutrino double-beta (
$$2\nu \beta \beta $$
2
ν
β
β
) decay of
$$^{100}$$
100
Mo to the ground state of
$$^{100}$$
100
Ru using lithium molybdate (
...$$\hbox {Li}_2^{\;\;100}\hbox {MoO}_4$$
Li
2
100
MoO
4
) scintillating bolometers. The detectors were developed for the CUPID-Mo program and operated at the EDELWEISS-III low background facility in the Modane underground laboratory (France). From a total exposure of 42.235 kg
$$\times $$
×
day, the half-life of
$$^{100}$$
100
Mo is determined to be
$$T_{1/2}^{2\nu }=7.12^{+0.18}_{-0.14}\,\mathrm {(stat.)}\pm 0.10\,\mathrm {(syst.)}\times 10^{18}$$
T
1
/
2
2
ν
=
7
.
12
-
0.14
+
0.18
(
stat
.
)
±
0.10
(
syst
.
)
×
10
18
years. This is the most accurate determination of the
$$2\nu \beta \beta $$
2
ν
β
β
half-life of
$$^{100}$$
100
Mo to date.
Abstract We report the measurement of the two-neutrino double-beta ($$2\nu \beta \beta $$ 2νββ ) decay of $$^{100}$$ 100 Mo to the ground state of $$^{100}$$ 100 Ru using lithium molybdate ($$\hbox ...{Li}_2^{\;\;100}\hbox {MoO}_4$$ Li2100MoO4 ) scintillating bolometers. The detectors were developed for the CUPID-Mo program and operated at the EDELWEISS-III low background facility in the Modane underground laboratory (France). From a total exposure of 42.235 kg$$\times $$ × day, the half-life of $$^{100}$$ 100 Mo is determined to be $$T_{1/2}^{2\nu }=7.12^{+0.18}_{-0.14}\,\mathrm {(stat.)}\pm 0.10\,\mathrm {(syst.)}\times 10^{18}$$ T1/22ν=7.12-0.14+0.18(stat.)±0.10(syst.)×1018 years. This is the most accurate determination of the $$2\nu \beta \beta $$ 2νββ half-life of $$^{100}$$ 100 Mo to date.
For the first time, amides and ureas based on both 5-nitroisoquinoline and 5-nitrosoisoquinoline were obtained by direct nucleophilic substitution of hydrogen in the 5-nitroisoquinoline molecule. In ...the case of urea and monosubstituted ureas, only 5-nitrosoisoquinoline-6-amine is formed under anhydrous conditions.
We report the measurement of the two-neutrino double-beta (
2
ν
β
β
) decay of
100
Mo to the ground state of
100
Ru using lithium molybdate (
Li
2
100
MoO
4
) scintillating bolometers. The detectors ...were developed for the CUPID-Mo program and operated at the EDELWEISS-III low background facility in the Modane underground laboratory (France). From a total exposure of 42.235 kg
×
day, the half-life of
100
Mo is determined to be
T
1
/
2
2
ν
=
7
.
12
-
0.14
+
0.18
(
stat
.
)
±
0.10
(
syst
.
)
×
10
18
years. This is the most accurate determination of the
2
ν
β
β
half-life of
100
Mo to date.
The thermal conductivity of a ZnWO.sub.4 single crystal in the principal crystallographic directions has been studied experimentally in the temperature range of 50-573 K, and the heat capacity of the ...single crystal has been measured in the range of 81-301 K. DOI: 10.1134/S1063783416040193
The scintillation crystal bismuth germanate Bi 4 Ge 3 O 12 (BGO) is widely used in many applications. The developed in the Nikolaev Institute of Inorganic Chemistry, Novosibirsk, Russia, unique ...technique allows routine production of top quality large sized BGO crystals. One of the important properties of the scintillation crystal is its radiation hardness. The intensive study of the radiation hardness of BGO crystals has been carried out by the collaboration of the institutes of Siberian Branch of the Russian Academy of Science, Novosibirsk. The influence on radiation hardness of the raw material purity and growth procedure has been studied. The final tests of the crystal radiation hardness were done by irradiation with gamma rays from 137 Cs radioactive source. The degradation of a light output of the best crystals is less than 10% after irradiation with expected at astrophysics experiment at satellite doses of 10-100 krad. Based on results of this research, the radiation hard BGO crystals for "INTEGRAL" and "ASTRO-H" satellite missions have been made. The self-recovering of the crystal light output is clearly seen. The time scale of the self-recovery strongly depends on a dose of the irradiation. It is days for 1 krad irradiation, weeks - for 10 krad irradiation and much more time is required for 100 krad irradiation. The all irradiated with 100 krad dose completely recover after annealing. It reveals that will be no essential degradation if this dose will be integrated over years of operation.
Neutrinoless double beta decay (0νββ) is a yet unobserved nuclear process that would demonstrate Lepton number violation, a clear evidence of beyond standard model physics. The process two neutrino ...double beta decay (2νββ) is allowed by the standard model and has been measured in numerous experiments. In this Letter, we report a measurement of 2νββ decay half-life of ^{100}Mo to the ground state of ^{100}Ru of 7.07±0.02(stat)±0.11(syst)×10^{18} yr by the CUPID-Mo experiment. With a relative precision of ±1.6% this is the most precise measurement to date of a 2νββ decay rate in ^{100}Mo. In addition, we constrain higher-order corrections to the spectral shape, which provides complementary nuclear structure information. We report a novel measurement of the shape factor ξ_{3,1}=0.45±0.03(stat)±0.05(syst) based on a constraint on the ratio of higher-order terms from theory, which can be reliably calculated. This is compared to theoretical predictions for different nuclear models. We also extract the first value for the effective axial vector coupling constant obtained from a spectral shape study of 2νββ decay.
The cross sections for the monitor reactions
27
Al(
p, x
)
24
Na,
27
Al(
p, x
)
22
Na, and
27
Al(
p, x
)
7
Be at 12 proton energies, 2605, 1598, 1199, 799, 600, 400, 249, 147.6, 97.2, 66.0, 44.6, and ...40.8 MeV, have been determined with 72 × 72-mm square and 10.5-mm-diameter round aluminum foils. The rates of the reactions of the production of
24
Na,
22
Na, and
7
Be in the foils in each irradiation run have been determined by
γ
spectrometry, whereas the number of protons transmitted through these foils has been determined using calibrated fast current transformers. The cross sections have been determined as the ratios of the corresponding reaction to the average proton fluence.
Abstract CUPID-Mo, located in the Laboratoire Souterrain de Modane (France), was a demonstrator for the next generation $$0\nu \beta \beta $$ 0 ν β β decay experiment, CUPID. It consisted of an array ...of 20 enriched Li $$_{2}$$ 2 $$^{100}$$ 100 MoO $$_4$$ 4 bolometers and 20 Ge light detectors and has demonstrated that the technology of scintillating bolometers with particle identification capabilities is mature. Furthermore, CUPID-Mo can inform and validate the background prediction for CUPID. In this paper, we present a detailed model of the CUPID-Mo backgrounds. This model is able to describe well the features of the experimental data and enables studies of the $$2\nu \beta \beta $$ 2 ν β β decay and other processes with high precision. We also measure the radio-purity of the Li $$_{2}$$ 2 $$^{100}$$ 100 MoO $$_4$$ 4 crystals which are found to be sufficient for the CUPID goals. Finally, we also obtain a background index in the region of interest of 3.7 $$^{+0.9}_{-0.8}$$ - 0.8 + 0.9 (stat) $$^{+1.5}_{-0.7}$$ - 0.7 + 1.5 (syst) $$\times ~10 ^{-3}$$ × 10 - 3 counts/ $$\Delta E_{\text {FWHM}}/\text {mol}_{\text {iso}}/\text {year},$$ Δ E FWHM / mol iso / year , the lowest in a bolometric $$0\nu \beta \beta $$ 0 ν β β decay experiment.
Abstract The CUPID-Mo experiment to search for 0 $$\nu \beta \beta $$ ν β β decay in $$^{100}$$ 100 Mo has been recently completed after about 1.5 years of operation at Laboratoire Souterrain de ...Modane (France). It served as a demonstrator for CUPID, a next generation 0 $$\nu \beta \beta $$ ν β β decay experiment. CUPID-Mo was comprised of 20 enriched $$\hbox {Li}_{{2}}$$ Li 2 $$^{100}$$ 100 $$\hbox {MoO}_4$$ MoO 4 scintillating calorimeters, each with a mass of $$\sim 0.2$$ ∼ 0.2 kg, operated at $$\sim 20$$ ∼ 20 mK. We present here the final analysis with the full exposure of CUPID-Mo ( $$^{100}$$ 100 Mo exposure of 1.47 $$\hbox {kg} \times \hbox {year}$$ kg × year ) used to search for lepton number violation via 0 $$\nu \beta \beta $$ ν β β decay. We report on various analysis improvements since the previous result on a subset of data, reprocessing all data with these new techniques. We observe zero events in the region of interest and set a new limit on the $$^{100}$$ 100 Mo 0 $$\nu \beta \beta $$ ν β β decay half-life of $$T_{1/2}^{0\nu }$$ T 1 / 2 0 ν $$> {1.8}\times 10^{24}$$ > 1.8 × 10 24 year (stat. + syst.) at 90% CI. Under the light Majorana neutrino exchange mechanism this corresponds to an effective Majorana neutrino mass of $$\left<m_{\beta \beta }\right>$$ m β β $$<~{(0.28{-}0.49)} $$ < ( 0.28 - 0.49 ) eV, dependent upon the nuclear matrix element utilized.
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