Fri·Mar 18, 2022Friday·March 18, 2022

1. 01*

   Electromagnetic moments of scandium isotopes and $N=28$ isotones in the distinctive $0f_{7/2}$ orbit

   S. W. Bai🇨🇳 · Á. Koszorús🇧🇪 · B. S. Hu🇨🇦 · X. F. Yang🇨🇳 · J. Billowes🇬🇧 · C. L. Binnersley🇬🇧 · M. L. Bissell🇬🇧 · K. Blaum🇩🇪 · P. Campbell🇬🇧 · B. Cheal🇬🇧 · T. E. Cocolios🇧🇪 · R. P. de Groote🇫🇮 and 22 other authors

   The electric quadrupole moment of ${}^{49}$Sc was measured by collinear laser spectroscopy at CERN-ISOLDE to be $Q_{\mathrm{s}}=-0.159(8)$ $e$b, and a nearly tenfold improvement in precision was reached for the electromagnetic moments of ${}^{47,49}$Sc. The single-particle behavior and nucleon-nucleon correlations are investigated with the electromagnetic moments of $Z=21$ isotopes and $N=28$ isotones as valence neutrons and protons fill the distinctive $0f_{7/2}$ orbit, respectively, located between magic numbers, 20 and 28. The experimental data are interpreted with shell-model calculations using an effective interaction, and ab-initio valence-space in-medium similarity renormalization group calculations based on chiral interactions. These results highlight the sensitivity of nuclear electromagnetic moments to different types of nucleon-nucleon correlations, and establish an important benchmark for further developments of theoretical calculations.

   nucl-exnucl-thPLB(2022)·9 citations
2. 02*

   Study on nuclear $\alpha$-decay energy by an artificial neural network with pairing and shell effects

   Hong-Qiang You · Zheng-Zhe Qu · Ren-Hang Wu · Hao-Ze Su · Xiao-Tao He🇨🇳

   We build and train the artificial neural network model (ANN) based on the experimental $\alpha$-decay energy ($Q_{\alpha }$) data. Besides decays between the ground states of parent and daughter nuclei, decays from the ground state of parent nuclei to the excited state of daughter nuclei are also included. By this way, the number of samples are increased dramatically. The results calculated by ANN model reproduce the experimental data with a good accuracy. The root-mean-square (rms) relative to the experiment data is 0.105 MeV. The influence of different input is investigated. It is found that either the shell effect or the pairing effect results in an obvious improvement of the predictive power of ANN model, and the shell effect plays a more important role. The optimal result can be obtained as both the shell and pairing effects are considered simultaneously. Application of ANN model in prediction of the $\alpha$-decay energy shows the neutron magic number at $N=184$, and a possible sub-shell gap around $N=174$ or 176 in the superheavy nuclei region.

   ↳ nucl-thnucl-exSymmetry(2022)·3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.