PaperPanorama

Nuclear Theory·nucl-th

Monday·May 19, 2025

7 papers4 primary·3 cross-listed

  1. 01

    Probing the refined performance of the Categorical-Boosting algorithm to the Hartree-Fock-Bogoliubov mass model with different Skyrme forces

    Jin-Liang Guo · Hua-Lei Wang · Zhen-Zhen Zhang · Min-Liang Liu

    Nuclear mass can offer profound insights into many physical branches, e.g., nuclear physics and astrophysics, while the predicted accuracy by nuclear mass models is usually far from satisfactory until now, especially within the fully microscopic self-consistent mean-field theory. In this project, we present the predictive power for the binding energy within the the Hartree-Fock-Bogoliubov (HFB) methods with six widely used Skyrme forces (SkM*, SkP, SLy4, SV-min, UNEDF0 and UNEDF1) and evaluate the refined performance of the machine learning based on a novel Categorical Boosting (CatBoost) algorithm to the Skyrme HFB mass models. The root-mean-square (rms) deviations between the bare HFB calculations with different Skyrme forces and the available experimental data range from the minimum, about 1.43 MeV, for the UNEDF0 parameter set to the maximum, about 7.03 MeV, for the SkM* paraterer set. For the CatBoost-refined HFB predictions, the predictive power can be significantly improved. All the prediction accurancies on the testing set can reach the level around 0.2 MeV and, meanwhile, the large model bias can be reduced. The model-repair coefficients for the adopted Skyrme parameter sets are uniformly more than 80\%. Moreover, for 21 newly measured nuclei outside AME2020, the predicted masses by the CatBoost-refined HFB models are also in good agreement with the experimental data, illustrating their good generalization abilities. Intrestingly, it is found that the optimal Skyrme parameter set that possesses the highest predictive power for the bare HFB mass calculations may be not the best candidate for the CatBoost-refined HFB model, indicating the different abilities of picking up the missing ``physics'' for different Skyrme forces by the CatBoost algorithm.

    nucl-thPRC(2025)·4 citations
  2. 02

    Collective excited states at small amplitude in neutron elastic scattering at low-energies

    Do Quang Tam · Nguyen Hoang Tung · Nguyen Hoang Phuc · T. V. Nhan Hao

    We investigate the contributions of isoscalar and isovector collective excitations in the neutron elastic scattering of O, Ca, Ca, and Pb nuclei by using a microscopic optical potential (MOP) derived from nuclear structure models based on self-consistent mean-field approaches. Particular attention is given to the role of these collective modes in shaping the imaginary part of the MOP and the resulting angular distributions. Our analysis indicates that both isoscalar and isovector contributions are significant for all considered targets, especially for light and medium targets. Furthermore, the Coulomb interaction is found to play an important role in describing absorption mechanisms and reproducing the experimental angular distributions.

    nucl-thIJMPE(2026)·0 citations
  3. 03

    Systematic analysis of double Gamow-Teller sum rules

    Hong-Jin Xie · Yi Lu · Shu-Yuan Liang · Yang Lei · Calvin W. Johnson

    Sum rules are important bulk properties of transition strength functions for atomic nuclei. Unlike the Ikeda sum rule for single Gamow-Teller transition, double Gamow-Teller transition sum rules rely on the details of many-body wavefunctions. We approximate the shell model ground state with nucleon-pair condensates, by projection after variation, and compute double Gamow-Teller (DGT) transition sum rules from both and directions. By systematic investigation of DGT sum rules of even-even nuclei in the , major shells, we quantitatively estimate the model-dependent fractions in the sum rules, and analyze the importance of double isospin-analogue state in the DGT strength function.

    nucl-thSymmetry(2025)·1 citation
  4. 04

    Neural Quantum States for Light Nuclei with Chiral Two- and Three-Body Interactions

    Pengsheng Wen🇺🇸 · Alexandros Gezerlis🇨🇦 · Jeremy W. Holt🇺🇸

    Finding high-quality trial wave functions for quantum Monte Carlo calculations of light nuclei requires a strong intuition for modeling the interparticle correlations as well as large computational resources for exploring the space of variational parameters. Moreover, for systems with three-body interactions, the wave function should account for many-body effects beyond simple pairwise correlations. In this work, we design neural networks that efficiently incorporate these factors to generate expressive wave function Ansätze for light nuclei using variational Monte Carlo. Our neural-network approach for nuclei can capture, already at the level of variational Monte Carlo, the overwhelming majority of the ground-state energy estimated by Green's Function Monte Carlo (GFMC). It achieves a ground-state energy within of the GFMC result for using the softest chiral interaction, representing a substantial improvement over standard variational Monte Carlo, which exhibits a deviation. The result indicates the potential of neural networks to construct effective trial wave functions for quantum Monte Carlo calculations.

    nucl-thPRL(2026)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE