Nuclear Theory·nucl-th

Tuesday·December 9, 2025

17 papers—9 primary·8 cross-listed

01
[Submitted on 6 Dec 2025]
The influence of heavy quark potential on quarkonium production in quark-gluon plasma
Taesoo Song🇩🇪 · Jiaxing Zhao🇩🇪
Remler formalism is the Wigner projection of a two particle state to bound states, which is carried out when the bound state begins to exist or when one of the two particles scatters in medium. This method has been successfully applied to quarkonium production in box simulations and in heavy-ion collisions. In this study this method is extended to strongly bound states with considerable binding energies by taking into account the potential energy between heavy quark pairs in the quark-gluon plasma (QGP). We find that an attractive heavy-quark potential enhances quarkonium production and the results are consistent with those from the statistical model in box simulations, if a proper spatial cutoff is introduced to the potential to mimic quantum effects.
Comments:
12 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.06339 [pdf]
PRC(2026)·4 citations
02
[Submitted on 7 Dec 2025]
Understanding Charge Radii with Machine Learning: Discovering Physics Expressions
B. Maheshwari🇫🇷 · P. Van Isacker🇫🇷
We introduce a robust, interpretable machine learning (ML) framework that combines numerical regression for high-accuracy predictions with symbolic regression to uncover the underlying physics. This hybrid approach effciently derives analytical expressions by leveraging the smoothed predictions of optimized ML models, a significant acceleration over direct symbolic regression on raw experimental data. We apply this framework, as an example, to nuclear charge radii across the nuclear chart, notably including light nuclei that are often excluded from such studies. We employ Light Gradient Boosting Machine (LGBM) and Gaussian Process Regression (GPR) models to map correlations between charge radii and key physical features: mass $A^{1/3}$ and proton number $Z^{1/3}$ dependencies, total binding energy, and for the first time, the pairing gap. Our models are rigorously trained using four-fold cross-validation with automated hyperparameter optimization, ensuring robustness and generalizability, which is critical for the typically small and skewed datasets in nuclear physics. Finally, we distill the knowledge from the initial LGBM and GPR models into simplified, interpretable mathematical expressions via symbolic regression, white-boxing these ML models. The derived formulas provide physical insights comparable to traditional many-body models and demonstrate a powerful pathway for physics expression discovery guided by ML.
Comments:
To Appear in Physics Letters B
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2512.06683 [pdf]
PLB(2026)·2 citations
03
[Submitted on 8 Dec 2025]
Direct Boundary Matching: A Bound-State Technique for Nuclear Scattering with Lagrange-Legendre Functions
Jin Lei
I present a direct boundary matching method (DBMM) for solving nuclear scattering problems using Lagrange-Legendre basis functions. This approach belongs to the family of bound-state techniques for the continuum, reformulating scattering problems into a localized, square-integrable ( $L^{2}$ ) representation. The key feature is the direct incorporation of the outgoing wave boundary condition into the last row of the matrix equation, eliminating the need for Bloch operators and two-step matching procedures required in traditional R-matrix methods. Unlike the complex scaling method that rotates coordinates into the complex plane, DBMM operates entirely in real coordinate space. The formalism is extended to coupled-channel problems, where the wave function decomposition naturally leads to an effective source potential that distinguishes between the entrance channel and other channels. Benchmark calculations for p~+~ $^{12}$ C scattering demonstrate excellent agreement with the Numerov integration method.
Comments:
8 pages, 3 figures. Published version
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.07111 [pdf]
PRC(2026)·2 citations
04
[Submitted on 8 Dec 2025]
Bayesian Inference of Heavy-Quark Dissipation and Jet Transport Parameters from D-Meson observables in heavy-ion collisions at the LHC energies
Xu-Fei Xue🇨🇳 · Zi-Xuan Xu🇨🇳 · Wei Dai🇨🇳 · Jiaxing Zhao🇩🇪 · Ben-Wei Zhang🇨🇳
We perform the first simultaneous Bayesian inference of the temperature-dependent heavy-quark spatial diffusion coefficient $2 π T D_{s}$ and the scaled jet transport coefficient $q^/ T^{3}$ in the quark-gluon plasma, utilizing $D$ -meson nuclear modification factor $R_{AA}$ and elliptic flow $v_{2}$ data from Pb-Pb collisions at $s_{NN} = 5.02 TeV$ . The analysis employs a unified improved Langevin transport model that incorporates both collisional and radiative energy loss, followed by coalescence plus fragmentation hadronization. The posterior distributions of the parameters of $q^/ T^{3}$ and those of $2 π T D_{s}$ are well constrained, and compared with the results of theoretical models or other experimental data extraction, respectively. The $30 - 50%$ centrality data provide significantly stronger constraints than the $0 - 10%$ data. The extracted ratio $q^/ κ$ between the quark jet transport and heavy-quark diffusion coefficients exhibits a non-monotonic temperature dependence, deviating from the value $2$ estimated from the definition, with a value interval spanning 0.25--0.8 corresponding to the mean values of the inferred parameters. This work establishes a data-driven quantitative relationship between these two fundamental transport properties in the same observables, offering crucial insight into their interplay in the strongly coupled medium.
Comments:
10 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2512.07169 [pdf]
PRC(2026)·3 citations
05
[Submitted on 8 Dec 2025]
Shell-model calculation with density-dependent interaction for $p f$ -shell nuclei
K. Yoshinaga · N. Shimizu · T. Nakatsukasa
Shell-model calculations with density-dependent interactions are performed to investigate $p f$ -shell nuclei, examining the ground-state energies, low-lying spectra, and $E 2$ transition probabilities. The density-dependent terms in the interaction are self-consistently determined using the shell-model wave function for the ground state. We test three density-dependent interactions adapted from density functionals of Gogny-D1S, Gogny-GT2, and M3Y-P6. The shell-model results satisfactorily agree with the experimental data. However, the Gogny-D1S and Gogny-GT2 fail to reproduce the magicity of $N = 28$ , while it is properly described by the M3Y-P6 functional.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.07376 [pdf]
PTEP(2026)·0 citations
06
[Submitted on 8 Dec 2025]
Absence of charged pion condensation in a magnetic field with parallel rotation
Puyuan Bai🇨🇳 · Lianyi He🇨🇳
We investigate the critical temperature of a relativistic Bose-Einstein condensate of charged bosons driven by rotation in a parallel magnetic field [Y. Liu and I. Zahed, Phys. Rev. Lett. 120, 032001 (2018)]. For non-interacting bosons, the critical temperature can only be determined for a system with fixed angular momentum. We find that the critical temperature of the non-interacting system vanishes due to the fact that the system is quasi-one-dimensional, indicating that non-interacting bosons cannot undergo Bose-Einstein condensation. For interacting bosons, we investigate a system with quartic self-interaction. We show that the order parameter vanishes and the off-diagonal long-range order is absent at any nonzero temperature because of the quasi-one-dimensional feature, in accordance with the Coleman-Mermin-Wagner-Hohenberg theorem.
Comments:
16 pages, 1 figure
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Theory (hep-th)
arXiv:
2512.07473 [pdf]
PRD(2026)·4 citations
07
[Submitted on 8 Dec 2025]
Gamow shell model predictions for six-proton unbound nucleus $^{20}$ Si
J.L. Wang · M.R. Xie · K.H. Li · P.Y. Wang · N. Michel · Q. Yuan · J.G. Li
Proton-rich nuclei beyond the proton drip line are of great interest in nuclear structure physics, due to exotic phenomena such as proton emissions and the Thomas-Ehrman shift (TES). In this work, we employ the Gamow shell model (GSM) to investigate the structure and decay of $^{20}$ Si, a candidate for six-proton (6 $p$ ) emission, which can be produced via two-neutron knockout from the drip line nucleus $^{22}$ Si. We predict that its ground state decays via $6 p$ emission to the ground state of $^{14}$ O, with a decay energy $E_{6 p} = 10.125$ MeV and a width of 371~keV. A $2^{+}$ state is predicted at 1.7 MeV, comparable with that in $^{18}$ Mg, indicating the disappearance of the $Z = 14$ magic number in $^{20}$ Si. Instead, analyses of the many-body configurations and the average occupancies of the mirror states suggest the presence of $d y nami c$ TES in low-lying states of $^{19}$ Al/ $^{19}$ C and $^{20}$ Si/ $^{20}$ C. Further evidence is provided by analyzing the contributions of different components of the GSM Hamiltonian. Moreover, this study offers the first theoretical description of $^{20}$ Si and guidance for future experiments.
Comments:
8 pages, 4 figures, 1 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.07594 [pdf]
PLB(2026)·4 citations
08
[Submitted on 8 Dec 2025]
Generalised Bohr Hamiltonian for Gogny interactions
C. Azam🇫🇷 · D. Davesne🇫🇷 · Y.Lallouet🇫🇷 · L. Próchniak🇵🇱 · M. Frosini🇫🇷 · A.Pastore🇫🇷
Using a generalised Bohr Hamiltonian formalism together with the Gogny interaction to provide a microscopic input of the required mass parameters, we present the potential energy surface and the evolution of the first excited 2 $^{+}$ state for the gadolinium isotopic chain. We observe that the energies and electromagnetic transitions of low-lying states are fairly similar for the various parametrisations and are in good agreement with experimental data.
Comments:
Presented at the XXXVIII Mazurian Lakes Conference on Physics, Piaski, Poland, August 31 --September 6, 2025
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.07601 [pdf]
Acta Phys.Polon.Supp.(2026)·0 citations
09
[Submitted on 8 Dec 2025]
Trapped Fermions Through Kolmogorov-Arnold Wavefunctions
Paulo F. Bedaque · Jacob Cigliano · Hersh Kumar · Srijit Paul · Suryansh Rajawat
We investigate a variational Monte Carlo framework for trapped one-dimensional mixture of spin- $\frac{1}{2}$ fermions using Kolmogorov-Arnold networks (KANs) to construct universal neural-network wavefunction ansätze. The method can, in principle, achieve arbitrary accuracy, limited only by the Monte Carlo sampling and was checked against exact results at sub-percent precision. For attractive interactions, it captures pairing effects, and in the impurity case it agrees with known results. We present a method of systematic transfer learning in the number of network parameters, allowing for efficient training for a target precision. We vastly increase the efficiency of the method by incorporating the short-distance behavior of the wavefunction into the ansätz without biasing the method.
Comments:
18 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); cond-mat.dis-nn (cond-mat.dis-nn); Quantum Gases (cond-mat.quant-gas); Computational Physics (physics.comp-ph); Quantum Physics (quant-ph)
arXiv:
2512.07800 [pdf]
1 citation

Affiliations

first authorsco-authorsvia INSPIRE