Predictions of α decay half-lives for even–even superheavy nuclei with 104 ≤ Z ≤ 128 based on two-potential approach within cluster-formation model

2019 ◽  
Vol 28 (10) ◽  
pp. 1950089 ◽  
Author(s):  
Hong-Ming Liu ◽  
Jun-Yao Xu ◽  
Jun-Gang Deng ◽  
Biao He ◽  
Xiao-Hua Li
Keyword(s):  
Cluster Formation ◽  
Magic Number ◽  
Neutron Number ◽  
Superheavy Nuclei ◽  
Formation Model ◽  
Α Decay ◽  
Potential Approach ◽  
Changing Trend ◽  
Energy Formula ◽  
Neutron Magic Number

In this work, we systematically study the [Formula: see text] decay half-lives of 170 even–even nuclei with [Formula: see text] within the two-potential approach while the [Formula: see text] decay preformation factor [Formula: see text] is obtained by the cluster-formation model. The calculated results can well reproduce the experimental data. In addition, we extend this model to predict the [Formula: see text] decay half-lives of 64 even–even nuclei with [Formula: see text] whose [Formula: see text] decay is energetically allowed or observed but not yet quantified. For comparison, the two famous models i.e., SemFIS proposed by Poenaru et al. [Europhys. Lett. 77 (2007) 62001] and UDL proposed by Qi et al. [Phys. Rev. Lett. 103 (2009) 072501] are used. The predicted results of these models are basically consistent. At the same time, through analyzing the changing trend of [Formula: see text] decay energy [Formula: see text] of [Formula: see text] and 128 isotopes nuclei with the increasing of neutron number N and that of [Formula: see text] decay preformation factor [Formula: see text] of those isotopes even–even nuclei with the increasing of neutron number N, [Formula: see text] may be a new neutron magic number.

scholarly journals The globular cluster system of the Auriga simulations

2020 ◽  
Vol 496 (1) ◽  
pp. 638-648 ◽  
Author(s):  
Timo L R Halbesma ◽  
Robert J J Grand ◽  
Facundo A Gómez ◽  
Federico Marinacci ◽  
Rüdiger Pakmor ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Milky Way ◽  
Cluster Formation ◽  
Solar Radius ◽  
High Mass ◽  
Formation Model ◽  
The Galaxy ◽  
High Mass Loss ◽  
Globular Cluster System ◽  
Varying Mass

ABSTRACT We investigate whether the galaxy and star formation model used for the Auriga simulations can produce a realistic globular cluster (GC) population. We compare statistics of GC candidate star particles in the Auriga haloes with catalogues of the Milky Way (MW) and Andromeda (M31) GC populations. We find that the Auriga simulations do produce sufficient stellar mass for GC candidates at radii and metallicities that are typical for the MW GC system (GCS). We also find varying mass ratios of the simulated GC candidates relative to the observed mass in the MW and M31 GCSs for different bins of galactocentric radius metallicity (rgal–[Fe/H]). Overall, the Auriga simulations produce GC candidates with higher metallicities than the MW and M31 GCS and they are found at larger radii than observed. The Auriga simulations would require bound cluster formation efficiencies higher than 10 per cent for the metal-poor GC candidates, and those within the Solar radius should experience negligible destruction rates to be consistent with observations. GC candidates in the outer halo, on the other hand, should either have low formation efficiencies, or experience high mass-loss for the Auriga simulations to produce a GCS that is consistent with that of the MW or M31. Finally, the scatter in the metallicity as well as in the radial distribution between different Auriga runs is considerably smaller than the differences between that of the MW and M31 GCSs. The Auriga model is unlikely to give rise to a GCS that can be consistent with both galaxies.

Formation of α clusters in dilute neutron-rich matter

Science ◽  
2021 ◽  
Vol 371 (6526) ◽  
pp. 260-264 ◽  
Author(s):  
Junki Tanaka ◽  
Zaihong Yang ◽  
Stefan Typel ◽  
Satoshi Adachi ◽  
Shiwei Bai ◽  
...  
Keyword(s):  
Cross Sections ◽  
Cluster Formation ◽  
Reaction Cross ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Heavy Nuclei ◽  
Α Decay ◽  
Neutron Skin Thickness ◽  
Reaction Cross Sections ◽  
Α Particles

The surface of neutron-rich heavy nuclei, with a neutron skin created by excess neutrons, provides an important terrestrial model system to study dilute neutron-rich matter. By using quasi-free α cluster–knockout reactions, we obtained direct experimental evidence for the formation of α clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between α-cluster formation and the neutron skin. This result, in turn, calls for a revision of the correlation between the neutron-skin thickness and the density dependence of the symmetry energy, which is essential for understanding neutron stars. Our result also provides a natural explanation for the origin of α particles in α decay.

Predictions for the α decay of superheavy nuclei of Z = 119 − 120 isotopes

2021 ◽  
pp. 122250
Author(s):  
Haitao Yang ◽  
Zhongxia Zhao ◽  
Xiaopan Li ◽  
Yan Cai ◽  
Xiaojun Bao
Keyword(s):  
Superheavy Nuclei ◽  
Α Decay

REVIEW ON THEORETICAL STUDIES OF SUPERHEAVY NUCLEI

2006 ◽  
Vol 15 (07) ◽  
pp. 1587-1599 ◽  
Author(s):  
ZHONGZHOU REN ◽  
DINGHAN CHEN ◽  
CHANG XU
Keyword(s):  
Ground State ◽  
Large Mass ◽  
Mass Region ◽  
Superheavy Nuclei ◽  
Theoretical Studies ◽  
Shape Coexistence ◽  
Good Test ◽  
Α Decay ◽  
The Stability ◽  
Theoretical Results

Superheavy elements have provided a good test of the validity of both nuclear structure models and nuclear decay models in a large mass region. We firstly review the recent progress on theoretical studies of superheavy nuclei. Emphasis is placed on the structure and decay of superheavy nuclei. Then theoretical results of odd-odd nuclei with Z = 109 - 115 are presented and discussed. It is clearly demonstrated that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. In some cases superdeformation can become the ground state of superheavy nuclei and it is important for future studies of superheavy nuclei. This can lead to the existence of low-energy isomers in the superheavy region and it plays an important role for the stability of superheavy nuclei. As α-decay and spontaneous fission plays a crucial role for identifications of new elements, we also review some typical models of α-decay half-lives and spontaneous fissions half-lives. Some new views on superheavy nuclei are presented.

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