arXiv subjects

Xin-Hui Wu

Publications and source records attributed to Xin-Hui Wu.

8 recordsLinked to original sources

arXiv2026

Comparison of several model averaging methods in nuclear charge radius predictions

The performance of five model averaging methods, including the arithmetic mean (AM), weighted mean (WM), naive Bayesian model averaging (NBMA), principal component analysis (PCA), and power-moderated mean (PMM) methods, in nuclear charge radius predictions is investigated. Five commonly used nuclear charge radius models are adopted as inputs for the averaging procedures. The charge radius differences between the experimental data and the original nuclear models are analyzed and the results after considering the model averaging methods are also discussed. The calculations show that the NBMA method can provide the best root-mean-square (rms) deviation among these five model averaging methods. The PCA method can extract useful physical information and not only helps to interpret the model differences but also offers a feasible way to construct improved empirical models by recombining the principal components. In contrast to the other methods, whose results worsen upon including a new model with a larger rms deviation, the rms deviation of the PCA method remains almost unaffected. The PMM method is capable of integrating the strengths of various nuclear models and delivering reasonable uncertainty estimates not only in known regions but also in unknown ones. This method can automatically adjust data uncertainties to achieve consistency, and it can provide a tool for a smooth transition of the nuclear charge radius prediction from the WM to the AM. The extrapolation ability of these model averaging methods is checked by 66 newly observed data after year 2021. The calculations show that model averaging offers a reliable strategy for nuclear charge radius predictions, combining high accuracy on known data with robust extrapolation to new measurements. The charge radii and the odd-even staggering in calcium isotopes are also discussed.

nucl-th↗

arXiv2026

ML and AI for density functional theory: different priorities for Kohn-Sham and orbital-free DFT, for electronic and nuclear DFT

We overview similarities and, importantly, differences in computational bottlenecks and accuracy requirements that can be addressed with machine learning (ML) and artificial intelligence (AI) techniques in electronic and nuclear DFT. From these follow different promising methodological and algorithmic choices depending on whether one machine learns the exchange correlation (XC) functional, the kinetic energy functional (KEF), the density or the basis functions. In particular, while the popular deep neural networks remain a potent choice in the context of KS DFT, we highlight their disadvantages when building KEFs and highlight conceptual advantages - yet to be fully realized - of symbolic regression for both electronic and nuclear DFT. We point out promising approaches that can be carried from the more extensively investigated ML-enhanced electronic DFT to nuclear DFT.

physics.chem-ph↗

arXiv2026

Normal mode analysis within relativistic massive transport

In this paper, we address the normal mode analysis on the linearized Boltzmann equation for massive particles in the relaxation time approximation. One intriguing feature of massive transport is the coupling of the secular equations between the sound and heat channels. This coupling vanishes as the mass approaches zero. By utilizing the argument principle in complex analysis, we determine the existence condition for collective modes and find the onset transition behavior of collective modes previously observed in massless systems. We numerically determine the critical wavenumber for the existence of each mode under various values of the scaled mass. Within the range of scaled masses considered, the critical wavenumbers for the heat and shear channels decrease with increasing scaled mass, while that of the sound channel exhibits a non-monotonic dependence on the scaled mass. In addition, we analytically derive the dispersion relations for these collective modes in the long-wavelength limit. Notably, kinetic theory also incorporates collisionless dissipation effects, known as Landau damping. We find that the branch cut structure responsible for Landau damping differs significantly from the massless case: whereas the massless system features only two branch points, the massive system exhibits an infinite number of such points forming a continuous branch cut.

hep-ph↗

arXiv2026

Basis Representation for Nuclear Densities from Principal Component Analysis

We develop an efficient method to represent nuclear densities using basis functions extracted via Principal Component Analysis (PCA). Applying PCA to densities of 75 nuclei calculated with the relativistic continuum Hartree-Bogoliubov (RCHB) theory yields an orthogonal set of components that efficiently capture the dominant features of nuclear density distributions, which can be used as basis functions for nuclear density representation. The first five basis functions account for more than 99.999\% of the total variance, demonstrating the efficiency of these PCA basis functions. The PCA basis achieves significantly higher accuracy and faster convergence than the Fourier-Bessel and Sum-of-Gaussians methods for reconstructing both theoretical and experimental densities. This approach provides an efficient and robust representation of nuclear densities, offering a practical tool for experimental density representation and for theories where densities play a central role, such as the orbital-free density functional theory, or the double folding model for nuclear reactions.

nucl-th↗

arXiv2026

Optimized adiabatic-impulse protocol preserving Kibble-Zurek scaling with attenuated anti-Kibble-Zurek behavior

We propose an optimized adiabatic-impulse (OAI) protocol that substantially reduces the evolution time for crossing a quantum phase transition while preserving Kibble-Zurek (KZ) scaling. Near criticality, the control parameter is ramped linearly across the critical point at a rate characterized by a quench time $τ_Q$. Away from criticality, the evolution remains adiabatic and is tuned close to the threshold of adiabatic breakdown, as quantified by an adiabatic coefficient $ζ$ that scales as $τ_Q^α$. As a consequence, the total evolution time exhibits a sublinear power-law dependence on $τ_Q$, and the conventional linear quench is recovered in the limit $α\rightarrow\infty$. We apply the OAI protocol to the transverse Ising chain and numerically determine the minimal $ζ$ required for KZ scaling. We further investigate the nonequilibrium dynamics in the presence of a noisy field that can induce anti-Kibble-Zurek (AKZ) behavior. Within the OAI protocol, noise-induced defects is significantly attenuated due to the shorter evolution time. The optimal quench time at which the defect density is minimized obeys an altered universal power-law scaling with the noise strength. Finally, we generalize the OAI protocol to the nonlinear quenches and numerically demonstrate a marked reduction in noise-induced defects.

quant-ph↗

arXiv2024

Nuclear level density from relativistic density functional theory and combinatorial method

Nuclear level density is calculated with the combinatorial method based on the relativistic density functional theory including pairing correlations. The Strutinsky method is adopted to smooth the total state density in order to refine the prediction at low excitation energy. The impacts of pairing correlations and moments of inertia on the nuclear level density are discussed in detail. Taking $\mathrm{^{112}Cd}$ as an example, it is demonstrated that the nuclear level density based on the relativistic density functional PC-PK1 can reproduce the experimental data at the same level as or even better than the previous approaches.

nucl-th↗

arXiv2021

Sensitivity study of \emph{r}-process abundances to nuclear masses

The impact of nuclear mass uncertainties on the \emph{r}-process abundances has been systematically studied with the classical \emph{r}-process model by varying the mass of every individual nucleus in the range of $\pm0.1$ to $\pm3.0\ \mathrm{MeV}$ based on six different mass models. A new quantitative relation between the uncertainties of \emph{r}-process abundances and those of the nuclear masses is extracted, i.e., a mass uncertainty of $\pm0.5\ \mathrm{MeV}$ would lead to an abundance uncertainty of a factor around 2.5. It is found that this conclusion holds true for various mass models.

nucl-th↗

arXiv2017

Composition of nuclear matter with light clusters and Bose-Einstein condensation of $α$ particles

The Bose-Einstein condensation of $α$ partciles in the multicomponent environment of dilute, warm nuclear matter is studied. We consider the cases of matter composed of light clusters with mass numbers $A\leq 4$ and matter that in addition these clusters contains $\isotope[56]{Fe}$ nuclei. We apply the quasiparticle gas model which treats clusters as bound states with infinite life-time and binding energies independent of temperature and density. We show that the $α$ particles can form a condensate at low temperature $T\le 2$ MeV in such matter in the first case. When the $\isotope[56]{Fe}$ nucleus is added to the composition the cluster abundances are strongly modified at low temperatures, with an important implication that the $α$ condensation at these temperatures is suppressed.

nucl-th↗