The Evolution toward Electron Capture Supernovae: The Flame Propagation and the Pre-bounce Electron–Neutrino Radiation

2019 ◽  
Vol 871 (2) ◽  
pp. 153 ◽  
Author(s):  
Koh Takahashi ◽  
Kohsuke Sumiyoshi ◽  
Shoichi Yamada ◽  
Hideyuki Umeda ◽  
Takashi Yoshida
2019 ◽  
Vol 21 ◽  
pp. 4
Author(s):  
P. G. Giannaka ◽  
T. S. Kosmas

Nuclear electron capture posses prominent position among other weak interaction processes occuring in explosive nucleosynthesis. In particular, this process plays important role in the core-colapse of massive stars by modifying the electron to baryon ratio Ye. From a nuclear theory point of view, such processes may be studied by using the same nuclear methods (e.g. the quasi-particle random phase approximation, QRPA), employed in the present work with these used for the one-body charge changing nuclear reactions (β-decay modes, charged-current electron-neutrino absorption by nuclei, etc). In this work we calculate e−-capture cross sections on 56Fe using two different approaches. At first, original cross section calculations are perfored by using the pn-QRPA method considering all the accessible transitions of the final nucleus 56Mn. Secondly, we evaluate the Gamow-Teller strength distributions and obtain the cross sections at the limit of zero-momentum transfer. The agreement between the two methods is very good.


2019 ◽  
Vol 34 (17) ◽  
pp. 1950129
Author(s):  
R. Basak ◽  
V. I. Tsifrinovich

In this paper, we compute the spin excess for the neutrinos radiated in the process of electron capture beta decay of partially polarized nuclei. The results of computation are presented for the [Formula: see text] nuclei polarized by the strong hyperfine field in a ferromagnetic substance. This system was suggested as a possible source of monoenergetic neutrino radiation with a preferable direction of neutrino propagation. We directly compute the spin excess of radiated neutrinos and show that it is slightly greater than that estimated previously under simplifying assumptions.


1983 ◽  
Vol 122 (5-6) ◽  
pp. 461-464 ◽  
Author(s):  
S. Yasumi ◽  
G. Rajasekaran ◽  
M. Ando ◽  
F. Ochiai ◽  
H. Ikeda ◽  
...  

2017 ◽  
Vol 119 (12) ◽  
Author(s):  
P. C.-O. Ranitzsch ◽  
C. Hassel ◽  
M. Wegner ◽  
D. Hengstler ◽  
S. Kempf ◽  
...  

1982 ◽  
Author(s):  
B. Jonson ◽  
J. U. Andersen ◽  
G. J. Beyer ◽  
G. Charpak ◽  
A. De Rújula ◽  
...  

2019 ◽  
Vol 79 (12) ◽  
Author(s):  
C. Velte ◽  
F. Ahrens ◽  
A. Barth ◽  
K. Blaum ◽  
M. Braß ◽  
...  

AbstractThe determination of the effective electron neutrino mass via kinematic analysis of beta and electron capture spectra is considered to be model-independent since it relies on energy and momentum conservation. At the same time the precise description of the expected spectrum goes beyond the simple phase space term. In particular for electron capture processes, many-body electron-electron interactions lead to additional structures besides the main resonances in calorimetrically measured spectra. A precise description of the $$^{163}$$163Ho spectrum is fundamental for understanding the impact of low intensity structures at the endpoint region where a finite neutrino mass affects the shape most strongly. We present a low-background and high-energy resolution measurement of the $$^{163}$$163Ho spectrum obtained in the framework of the ECHo experiment. We study the line shape of the main resonances and multiplets with intensities spanning three orders of magnitude. We discuss the need to introduce an asymmetric line shape contribution due to Auger–Meitner decay of states above the auto-ionisation threshold. With this we determine an enhancement of count rate at the endpoint region of about a factor of 2, which in turn leads to an equal reduction in the required exposure of the experiment to achieve a given sensitivity on the effective electron neutrino mass.


2017 ◽  
Vol 850 (1) ◽  
pp. 43 ◽  
Author(s):  
David Radice ◽  
Adam Burrows ◽  
David Vartanyan ◽  
M. Aaron Skinner ◽  
Joshua C. Dolence

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Robert Hammann ◽  
Arnulf Barth ◽  
Andreas Fleischmann ◽  
Dennis Schulz ◽  
Loredana Gastaldo

AbstractThe electron capture in $$^{163}\mathrm {Ho}$$ 163 Ho experiment (ECHo) is designed to directly measure the effective electron neutrino mass by analysing the endpoint region of the $$^{163}\mathrm {Ho}$$ 163 Ho electron capture spectrum. We present a data reduction scheme for the analysis of high statistics data acquired with the first phase of the ECHo experiment, ECHo-1k, to reliably infer the energy of $$^{163}\mathrm {Ho}$$ 163 Ho events and discard triggered noise or pile-up events. On a first level, the raw data is filtered purely based on the trigger time information of the acquired signals. On a second level, the time profile of each triggered event is analysed to identify the signals corresponding to a single energy deposition in the detector. We demonstrate that events not belonging to this category are discarded with an efficiency above 99.8%, with a minimal loss of $$^{163}\mathrm {Ho}$$ 163 Ho events of about 0.7%. While the filter using the trigger time information is completely energy independent, a slight energy dependence of the filter based on the time profile is precisely characterised. This data reduction protocol will be important to minimise systematic errors in the analysis of the $$^{163}\mathrm {Ho}$$ 163 Ho spectrum for the determination of the effective electron neutrino mass.


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