Deformed shell model results for two-neutrino double-beta decay of 82Se

2011 ◽  
Vol 89 (11) ◽  
pp. 1101-1105 ◽  
Author(s):  
R. Sahu ◽  
P.C. Srivastava ◽  
V.K.B. Kota
Keyword(s):  
Shell Model ◽  
Beta Decay ◽  
Half Life ◽  
Model Space ◽  
Spectroscopic Properties ◽  
Double Beta Decay ◽  
Hartree Fock ◽  
The Past ◽  
Quenching Factor ◽  
Reasonable Description

The half-life for two-neutrino double-beta decay has been calculated for 82Se, within the framework of the deformed shell model (DSM) based on Hartree–Fock states employing a modified Kuo interaction in 2p3/2, 1f5/2, 2p1/2, and 1g9/2 space with single particle energies (relative to a 56Ni core) for the four orbitals taken as 0.0, 0.78, 1.08, and 4.25 MeV, respectively. A reasonable description is obtained for the spectroscopic properties of yrast levels in 82Se, and similarly in the past 82Kr was studied successfully using DSM. The half-life calculated using DSM is ∼3.56 × 1020 a compared to the experimental value (0.92 ± 0.07) × 1020 a. We have also recalculated the half-life by including the 1f7/2 orbit in the preceding model space using the fpg interaction introduced by Sorlin et al. (Phys. Rev. Lett. 88, 092501 (2002)). The calculated half-life is 2.05 × 1019 a (0.58 × 1020 a if we include the quenching factor of 0.77).

scholarly journals Deformed shell model results for neutrinoless double beta decay of nuclei in A = 60 - 90 region

2015 ◽  
Vol 24 (03) ◽  
pp. 1550022 ◽  
Author(s):  
R. Sahu ◽  
V. K. B. Kota
Keyword(s):  
Shell Model ◽  
Beta Decay ◽  
Good Description ◽  
Effective Interaction ◽  
Model Space ◽  
Spectroscopic Properties ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Hartree Fock ◽  
Transition Matrix Elements

Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay (Oνββ or OνDBD) of 70 Zn , 80 Se and 82 Se nuclei are calculated within the framework of the deformed shell model (DSM) based on Hartree–Fock (HF) states. For 70 Zn , jj44b interaction in 2p3/2, 1f5/2, 2p1/2 and 1g9/2 space with 56 Ni as the core is employed. However, for 80 Se and 82 Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for 70 Zn . The above model space was used in many recent shell model (SM) and interacting boson model (IBM) calculations for nuclei in this region. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are 1.1 × 1026, 2.3 × 1027 and 2.2 × 1024 yr for 70 Zn , 80 Se and 82 Se , respectively.

scholarly journals DEFORMED SHELL MODEL RESULTS FOR TWO-NEUTRINO POSITRON DOUBLE BETA DECAY OF 84Sr

2011 ◽  
Vol 20 (08) ◽  
pp. 1723-1733 ◽  
Author(s):  
R. SAHU ◽  
V. K. B. KOTA
Keyword(s):  
Shell Model ◽  
Beta Decay ◽  
Single Particle ◽  
Double Beta Decay ◽  
Orbital Energy ◽  
Decay Modes ◽  
Fock States ◽  
Hartree Fock ◽  
Model Based ◽  
Reasonable Description

Half-lives [Formula: see text] for two-neutrino positron double beta decay modes β+ EC/ECEC are calculated for 84 Sr , a nucleus of current experimental interest, within the framework of the deformed shell model based on Hartree–Fock states employing a modified Kuo interaction in (2p3/2, 1f5/2, 2p1/2, 1g9/2) space. For a reasonable description of the spectra of 84 Sr and 84 Kr and to generate allowed GT strengths, the single particle energies of the proton and neutron 1g9/2 orbitals, relative to the 2p3/2 orbital energy, are chosen to be 3.5 MeV and 1.5 MeV for both 84 Sr and 84 Rb and 1.5 MeV and 1.5 MeV for 84 Kr . With this, the calculated half-lives for the β+ EC and ECEC modes are ~1026 yr and ~4×1024 yr respectively.

scholarly journals Double beta decay without invoking closure

2020 ◽  
Vol 1 ◽  
pp. 45
Author(s):  
G. Pantis ◽  
J. D. Vergados
Keyword(s):  
Shell Model ◽  
Beta Decay ◽  
Nuclear Matrix ◽  
Model Space ◽  
Double Beta Decay ◽  
Matrix Elements ◽  
Model Calculations ◽  
Closure Approximation ◽  
The Matrix

The nuclear matrix elements of PU operators entering in the 0v ßß-decay of 76Ge-->76Se have been calculated explicitly  in the context of QRPA within the model space 0f7/2 - 0h11/2. T h e validity of the closure approximation has been tested and seems to be quite satisfactory for those matrix elements which are not usually suppressed. Our results indicate that they are dominated by multipoles other than 0+ and 1+ and that the matrix elements are comparable to those of shell model calculations.

THE STATUS OF TWO-NEUTRINO AND NEUTRINOLESS DOUBLE BETA DECAY SEARCHES

1993 ◽  
Vol 02 (03) ◽  
pp. 507-546 ◽  
Author(s):  
M.K. MOE
Keyword(s):  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Experimental Activity ◽  
The Past ◽  
The Status ◽  
Substantial Progress ◽  
Direct Counting ◽  
Made In

Substantial progress has been made in double beta decay experiments in the past few years, including the beginning of sensitive new searches for neutrinoless double beta decay, and several additional positive detections of the two-neutrino mode by geochemical, radiochemical, and direct-counting techniques. This review discusses the recent experimental activity.

A measurement of the double beta decay half-life of 48Ca

1996 ◽  
Vol 48 (1-3) ◽  
pp. 213-215 ◽  
Author(s):  
A. Balysh ◽  
A. De Silva ◽  
V.I. Lebedev ◽  
K. Lou ◽  
M.K. Moe ◽  
...  
Keyword(s):  
Beta Decay ◽  
Half Life ◽  
Double Beta Decay

scholarly journals Neutrinoless Double-beta Decay Rates Around Mass 80 In The Nuclear Shell Model

2017 ◽  
Author(s):  
Kota Yanase ◽  
Naotaka Yoshinaga ◽  
Koji Higashiyama ◽  
Eri Teruya ◽  
Daisuke Taguchi
Keyword(s):  
Shell Model ◽  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Decay Rates ◽  
Double Beta Decay ◽  
Nuclear Shell Model ◽  
Nuclear Shell

scholarly journals Variation of NMEs of 0νββ for 48Ca with different components of NN interaction

2019 ◽  
Vol 223 ◽  
pp. 01057
Author(s):  
Shahariar Sarkar ◽  
Pawan Kumar ◽  
Kanhaiya Jha ◽  
P.K. Raina
Keyword(s):  
Beta Decay ◽  
Nuclear Matrix ◽  
Model Space ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Central Component ◽  
Spin Orbit ◽  
Matrix Elements ◽  
Nucleon Interaction ◽  
Total Interaction

We examine the sensitivity of nuclear matrix elements (NMEs) for light-neutrino exchange mechanism of neutrinoless double beta decay (0νββ) for 48Ca to the various components of two-nucleon interaction, GXPF1A, in fp model space. It is found that the contribution in NMEs coming from the central component is close to contribution from total interaction. The spin-orbit and tensor components are found canceling the contribution of each other.

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