scholarly journals K-Electron-Capture-to-Positron-Emission Ratio in the Decays ofO15andNe19

1972 ◽  
Vol 6 (4) ◽  
pp. 1132-1136 ◽  
Author(s):  
W. Leiper ◽  
R. W. P. Drever
Keyword(s):  
Electron Capture ◽  
Emission Ratio ◽  
Positron Emission

Electron capture to positron emission ratio in the decay of 44Sc

1976 ◽  
Vol 54 (24) ◽  
pp. 2396-2402 ◽  
Author(s):  
H. Stocker ◽  
A. P. Baerg
Keyword(s):  
Electron Capture ◽  
Ground State ◽  
Present Value ◽  
Total Electron ◽  
Coincidence Technique ◽  
Total Uncertainty ◽  
Emission Ratio ◽  
Positron Emission ◽  
Measured Ratio ◽  
Good Agreement

A new measurement of the total electron capture to positron emission ratio, e/β+, for the allowed beta decay of the ground state of 44Sc has been carried out by a 4πβ–γ coincidence technique using a pressurized gas proportional 4πβ counter and a Ge(Li) γ detector. The result is 0.0497 with a standard error of 0.0023 and an estimated maximum systematic uncertainty of 0.0026. By this method, the total uncertainty in the measured ratio has been reduced by about a factor of three compared to the most accurate of earlier results. The present value of e/β+ is in good agreement with all current theoretical estimates for allowed transitions and a detailed summary of these estimates is presented.

Study of Gamow–Teller strength and associated weak-rates on odd-A nuclei in stellar matter

2018 ◽  
Vol 27 (03) ◽  
pp. 1850019 ◽  
Author(s):  
Muhammad Majid ◽  
Jameel-Un Nabi ◽  
Muhammad Riaz
Keyword(s):  
Electron Capture ◽  
Theoretical Calculations ◽  
Random Phase ◽  
Measured Data ◽  
Particle Model ◽  
Transition Strength ◽  
Positron Emission ◽  
Stellar Temperature ◽  
Gamow Teller ◽  
Capture Rates

In a recent study by Cole et al. [A. L. Cole et al., Phys. Rev. C 86 (2012) 015809], it was concluded that quasi-particle random phase approximation (QRPA) calculations show larger deviations and overestimate the total experimental Gamow–Teller (GT) strength. It was also concluded that QRPA calculated electron capture rates exhibit larger deviation than those derived from the measured GT strength distributions. The main purpose of this study is to probe the findings of the Cole et al. paper. This study gives useful information on the performance of QRPA-based nuclear models. As per simulation results, the capturing of electrons that occur on medium heavy isotopes have a significant role in decreasing the ratio of electron-to-baryon content of the stellar interior during the late stages of core evolution. We report the calculation of allowed charge-changing transitions strength for odd-[Formula: see text] [Formula: see text]-shell nuclei ([Formula: see text]Sc and [Formula: see text]Mn) by employing the deformed pn-QRPA approach. The computed GT transition strength is compared with previous theoretical calculations and measured data. For stellar applications, the corresponding electron capture rates are computed and compared with rates using previously calculated and measured GT values. Our finding shows that our calculated results are in decent accordance with measured data. At higher stellar temperature, our calculated electron capture rates are larger than those calculated by independent particle model (IPM) and shell model. It was further concluded that at low temperature and high density regions, the positron emission weak-rates from [Formula: see text]Sc and [Formula: see text]Mn may be neglected in simulation codes.

scholarly journals Search for Double Beta Decay of 106Cd with an Enriched 106CdWO4 Crystal Scintillator in Coincidence with CdWO4 Scintillation Counters

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 182
Author(s):  
Pierluigi Belli ◽  
R. Bernabei ◽  
V.B. Brudanin ◽  
F. Cappella ◽  
V. Caracciolo ◽  
...  
Keyword(s):  
Electron Capture ◽  
Beta Decay ◽  
Ground State ◽  
Half Life ◽  
Double Beta Decay ◽  
Cadmium Tungstate ◽  
Positron Emission ◽  
Double Electron ◽  
Theoretical Predictions ◽  
Crystal Scintillator

Studies on double beta decay processes in 106Cd were performed by using a cadmium tungstate scintillator enriched in 106Cd at 66% (106CdWO4) with two CdWO4 scintillation counters (with natural Cd composition). No effect was observed in the data that accumulated over 26,033 h. New improved half-life limits were set on the different channels and modes of the 106Cd double beta decay at level of limT1/2∼1020−1022 yr. The limit for the two neutrino electron capture with positron emission in 106Cd to the ground state of 106Pd, T1/22νECβ+≥2.1×1021 yr, was set by the analysis of the 106CdWO4 data in coincidence with the energy release 511 keV in both CdWO4 counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range T1/2∼1021−1022 yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of 106Pd is restricted at the level of T1/20ν2K≥2.9×1021 yr.

scholarly journals Search for double $$\beta $$-decay modes of $$^{64}$$Zn using purified zinc

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
F. Bellini ◽  
M. Beretta ◽  
L. Cardani ◽  
P. Carniti ◽  
N. Casali ◽  
...  
Keyword(s):  
Electron Capture ◽  
High Purity ◽  
Rare Event ◽  
Germanium Detector ◽  
Background Level ◽  
Total Activity ◽  
Double Beta Decay ◽  
Raw Material ◽  
Decay Modes ◽  
Positron Emission

AbstractThe production of ultra-pure raw material is a crucial step to ensure the required background level in rare event searches. In this work, we establish an innovative technique developed to produce high-purity (99.999%) granular zinc. We demonstrate the effectiveness of the refining procedure by measuring the internal contaminations of the purified zinc with a high-purity germanium detector at the Laboratori Nazionali del Gran Sasso. The total activity of cosmogenic activated nuclides is measured at the level of a few mBq/kg, as well as limits on naturally occurring radionuclides are set to less than mBq/kg. The excellent radiopurity of the zinc sample allows us to search for electron capture with positron emission and neutrinoless double electron capture of $$^{64}$$ 64 Zn, setting the currently most stringent lower limits on their half-lives, $$T_{1/2}^{\varepsilon \beta ^+} > 2.7\times 10^{21}~\text {year}$$ T 1 / 2 ε β + > 2.7 × 10 21 year (90% CI), and $$T_{1/2}^{0\nu 2\varepsilon }> 2.6\times 10^{21}~\text {year}$$ T 1 / 2 0 ν 2 ε > 2.6 × 10 21 year (90% CI), respectively.

scholarly journals Detection prospects for the second-order weak decays of $$^{124}$$Xe in multi-tonne xenon time projection chambers

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Christian Wittweg ◽  
Brian Lenardo ◽  
Alexander Fieguth ◽  
Christian Weinheimer
Keyword(s):  
Electron Capture ◽  
Construction Materials ◽  
Reconstruction Algorithm ◽  
Second Order ◽  
Position Resolution ◽  
Baseline Design ◽  
Weak Decays ◽  
Time Projection Chambers ◽  
Positron Emission ◽  
Time Projection

AbstractWe investigate the detection prospects for two-neutrino and neutrinoless second-order weak decays of $$^{124}{\mathrm{Xe}}$$ 124 Xe – double-electron capture ($$0/2\upnu \text {ECEC}$$ 0 / 2 ν ECEC ), electron capture with positron emission ($$0/2\upnu \text {EC}\upbeta ^+$$ 0 / 2 ν EC β + ) and double-positron emission ($$0/2\upnu \upbeta ^+\upbeta ^+$$ 0 / 2 ν β + β + ) – in multi-tonne xenon time projection chambers. We simulate the decays in a liquid xenon medium and develop a reconstruction algorithm which uses the multi-particle coincidence in these decays to separate signal from background. This is used to compute the expected detection efficiencies as a function of position resolution and energy threshold for planned experiments. In addition, we consider an exhaustive list of possible background sources and find that they are either negligible in rate or can be greatly reduced using our topological reconstruction criteria. In particular, we draw two conclusions: First, with a theoretical half-life of $$T_{1/2}^{2\upnu \text {EC}\upbeta ^+} = (1.7 \pm 0.6)\cdot 10^{23}\,\text {year}$$ T 1 / 2 2 ν EC β + = ( 1.7 ± 0.6 ) · 10 23 year , the $$2\upnu \text {EC}\upbeta ^{+}$$ 2 ν EC β + decay of $$^{124}$$ 124 Xe will likely be detected in upcoming Dark Matter experiments (e.g. XENONnT or LZ), and their major background will be $$\upgamma $$ γ -rays from detector construction materials. Second, searches for the $$0\upnu \text {EC}\upbeta ^+$$ 0 ν EC β + decay mode will likely be background-free, and new parameter space may be within reach. To this end we investigate two different scenarios of existing experimental constraints on the effective neutrino mass. The necessary 500 kg-year exposure of $$^{124}$$ 124 Xe could be achieved by the baseline design of the DARWIN observatory, or by extracting and using the $$^{124}$$ 124 Xe from the tailings of the nEXO experiment. We demonstrate how a combination of $$^{124}$$ 124 Xe results with those from $$0\upnu \upbeta ^-\upbeta ^-$$ 0 ν β - β - searches in $$^{136}$$ 136 Xe could help to identify the neutrinoless decay mechanism.

Electron-capture to positon-emission ratio in the decay of 22Na

1967 ◽  
Vol 99 (1) ◽  
pp. 55-64 ◽  
Author(s):  
H. Leutz ◽  
H. Wenninger
Keyword(s):  
Electron Capture ◽  
Emission Ratio

The ratio of K-electron capture to positron emission in the decay of91Mo

1976 ◽  
Vol 2 (10) ◽  
pp. 723-739 ◽  
Author(s):  
M L Fitzpatrick ◽  
K W D Ledingham ◽  
M Campbell ◽  
A D Baillie ◽  
J Y Gourlay ◽  
...  
Keyword(s):  
Electron Capture ◽  
Positron Emission

Electron capture to positron emission ratios in the allowed decay of89Zr

1979 ◽  
Vol 5 (10) ◽  
pp. 1433-1444 ◽  
Author(s):  
A D Baillie ◽  
K W D Ledingham ◽  
J G Lynch ◽  
M Campbell
Keyword(s):  
Electron Capture ◽  
Positron Emission ◽  
Emission Ratios
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