Nuclear Theory·nucl-th

Monday·May 11, 2020

8 papers—5 primary·3 cross-listed

01
[Submitted on 8 May 2020]
Predictions of $α$ decay half-lives for even-even superheavy nuclei with $104 ⩽ Z ⩽ 128$ based on two-potential approach within cluster-formation model
H. M. Liu · J. Y. Xu · J. G. Deng · B. He · X. H. Li
In present work, we systematically study the $α$ decay half-lives of 170 even-even nuclei with $60 ⩽ Z ⩽ 118$ within the two-potential approach while the $α$ decay preformation factor $P_{α}$ 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 $α$ decay half-lives of 64 even-even nuclei with $104 ⩽ Z ⩽ 128$ whose $α$ decay is energetically allowed or observed but not yet quantified. For comparing, the two famous models i.e. SemFIS proposed by D. Poenaru $e t a l .$ [\href {https://doi.org/10.1209/0295-5075/77/62001}{Europhys. Lett. \textbf{77} (2007) 62001}] and UDL proposed by C. Qi $e t a l .$ [\href {https://doi.org/10.1103/PhysRevLett.103.072501}{Phys. Rev. Lett. \textbf{103} (2009) 072501}] are used. The predicted results of these models are basically consistent. At the same time, through analyzing the changing trend of $α$ decay energy $Q_{α}$ of \emph{Z} = 118, 120, 122, 124, 126 and 128 isotopes nuclei with the increasing of neutron number \emph{N} and that of $α$ decay preformation factor $P_{α}$ of those isotopes even-even nuclei with the increasing of neutron number \emph{N}, \emph{N} = 178 may be a new neutron magic number.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2005.03831 [pdf]
IJMPE(2020)·14 citations
02
[Submitted on 8 May 2020]
Systematic study of the $α$ decay preformation factor of nuclei around the $Z = 82$ , $N = 126$ shell closures within a generalized liquid drop model
Hong-Ming Liu · You-Tian Zou · Xiao-Pan · Xiao-Jun Bao · Xiao-Hua Li
In this work, we systematically study the $α$ decay preformation factors $P_{α}$ and $α$ decay half-lives of 152 nuclei around $Z$ = 82, $N$ = 126 closed shells based on a generalized liquid drop model while $P_{α}$ is extracted from the ratio of the calculated $α$ decay half-life to the experimental one. The results show that there is an obvious linear relationship between $P_{α}$ and the product of valance protons (holes) $N_{p}$ and valance neutrons (holes) $N_{n}$ . At the same time, we extract the $ $P_{α}$ values of even-even nuclei around $Z$ = 82, $N$ = 126 closed shells from the work of Sun \textit{et al.} [\href {https://doi.org/10.1088/1361-6471/aac981} {J. Phys. G: Nucl. Part. Phys. $45$ , 075106 (2018)}], in which the $P_{α}$ can be calculated by two different microscopic formulas. We find that the $P_{α}$ are also related to $N_{p} N_{n}$ . Combining with our previous works [Sun \textit{et al.}, \href {https://doi.org/10.1103/PhysRevC.94.024338} {Phys. Rev. C $94$ , 024338 (2016)}; Deng \textit{et al.}, \href {https://doi.org/10.1103/ PhysRevC 96.024318} {ibid. $96$ , 024318 (2017)}; Deng \textit{et al.}, \href {https://doi.org/10.1103/PhysRevC.97.044322} {ibid. $97$ , 044322 (2018)}] and the work of Seif \textit{et al.} [\href {http://dx.doi.org/10.1103/PhysRevC.84.064608}{Phys. Rev. C $84$ , 064608 (2011)}], we suspect that this phenomenon of linear relationship for the nuclei around those closed shells is model independent. It may be caused by the effect of the valence protons (holes) and valence neutrons (holes) around the shell closures. Finally, using the formula obtained by fitting the $P_{α}$ calculated by the generalized liquid drop model (GLDM), we calculate the $α$ decay half-lives of these nuclei. The calculated results are agree with the experimental data well.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2005.03836 [pdf]
CPC(2020)·21 citations
03
[Submitted on 8 May 2020]
Static quadrupole moments of nuclear chiral doublet bands
Q. B. Chen🇩🇪 · N. Kaiser🇩🇪 · Ulf-G. Meißner🇩🇪 · J. Meng🇨🇳
The static quadrupole moments (SQMs) of nuclear chiral doublet bands are investigated for the first time taking the particle-hole configuration $π (1 h_{11/2}) \otimes ν (1 h_{11/2})^{- 1}$ with triaxial deformation parameters in the range $26 0^{\circ} \leq γ \leq 27 0^{\circ}$ as examples. The behavior of the SQM as a function of spin $I$ is illustrated by analyzing the components of the total angular momentum. It is found that in the region of chiral vibrations the SQMs of doublet bands are strongly varying with $I$ , whereas in the region of static chirality the SQMs of doublet bands are almost constant. Hence, the measurement of SQMs provides a new criterion for distinguishing the modes of nuclear chirality. Moreover, in the high-spin region the SQMs can be approximated by an analytic formula with a proportionality to $cos γ$ for both doublet bands. This provides a way to extract experimentally the triaxial deformation parameter $γ$ for chiral bands from the measured SQMs.
Comments:
7 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2005.03865 [pdf]
PLB(2020)·22 citations
04
[Submitted on 8 May 2020]
Monopole and dipole transitions of the cluster states of 18O
T. Baba · M. Kimura
On the basis of an extended antisymmetrized molecular dynamics calculation, we study the cluster structure and the of the 0+ and 1- states of 18O. We discuss that several different kinds of cluster states appear in the excitation spectrum, and their monopole and dipole transitions are interesting fingerprints of unique cluster structure. We show that the monopole/dipole transitions are enhanced for the 14C+alpha cluster states, while they are hindered for the molecular-orbit state. We also point out that the ratio of the electric and isoscalar monopole transition strengths gives a good hint for the structure of the excited states.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2005.03934 [pdf]
PRC(2020)·7 citations
05
[Submitted on 8 May 2020]
Extracting a model quark propagator's spectral density
Zehao Zhu🇨🇳 · Khépani Raya🇨🇳 · Lei Chang🇨🇳
We propose a practical procedure to extrapolate the space-like quark propagator onto the complex plane, which follows the Schlessinger Point Method and the spectral representation of the propagator. As a feasible example, we employ quark propagators for different flavors, obtained from the solutions of the corresponding Dyson-Schwinger equation (DSE). Two different truncations are employed. Thus, the analytical structure of the quark propagator is studied, capitalizing on the current-quark mass dependence of the observed features.
Comments:
8 pages, 6 figures. It includes a new example with a beyond Rainbow-Ladder truncation
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2005.04181 [pdf]
PRD(2021)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

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

Systematic study of the α decay preformation factor of nuclei around the Z=82, N=126 shell closures within a generalized liquid drop model

Static quadrupole moments of nuclear chiral doublet bands

Monopole and dipole transitions of the cluster states of 18O

Extracting a model quark propagator's spectral density

Affiliations

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

Systematic study of the $α$ decay preformation factor of nuclei around the $Z = 82$ , $N = 126$ shell closures within a generalized liquid drop model