Nuclear Theory·nucl-th

Tuesday·March 31, 2026

30 papers—12 primary·18 cross-listed

01
A time-dependent wave-packet approach to reactions for quantum computation
Evan Rule🇺🇸 · Ionel Stetcu🇺🇸
We describe a method for obtaining the scattering matrix for nuclear or chemical reactions on a finite lattice. Aside from the preparation of the initial and final states as wave packets, the only other operation required is unitary time evolution, making this approach ideal for simulations on quantum hardware. The central quantity is a time-dependent overlap between incoming and outgoing wave packets whose Fourier transform corresponds to the scattering matrix at fixed energy, from which one can calculate elastic and inelastic cross sections for reactions involving two interacting clusters. Working in Cartesian coordinates enables an efficient encoding of the problem on quantum hardware via the first quantization mapping, with favorable qubit scaling for describing asymptotic scattering states. Within this framework, we describe a quantum algorithm for probing the scattering amplitude through different angles, including the forward direction, which provides access to the total cross section via the optical theorem. We demonstrate our methods through a series of numerical examples, for both elastic and inelastic processes, comparing against exact calculations. The techniques we describe can more readily be extended to a large number of constituent particles than other existing approaches, once fault-tolerant quantum hardware becomes available.
nucl-thquant-ph3 citations
02
Linking Electromagnetic Moments to Nuclear Interactions with a Global Physics-Driven Machine-Learning Emulator
Jose M. Munoz · Antoine Belley · Andreas Ekström · Gaute Hagen · Jason D. Holt · Ronald F. Garcia Ruiz
Understanding how specific components of the nuclear interaction shape observable properties of atomic nuclei remains a central challenge in nuclear structure research. While previous studies have focused on bulk observables such as nuclear energies and charge radii, it is unclear how distinct operator components of nuclear interactions impact complementary observables such as nuclear electromagnetic moments. Here, we develop a global, physics-constrained emulator to establish a quantitative link between electromagnetic moments and components of chiral nuclear forces. Unlike traditional sensitivity analyses that vary low-energy constants independently, we quantify parameter contributions while accounting for correlations within the physically supported parameter manifold. We show that, unlike bulk observables, electromagnetic moments probe complementary spin and isospin sectors of the interaction and exhibit a pronounced isotope-dependent sensitivity. These developments enable a quantitative assessment of the importance of prospective measurements, providing predictions with quantified uncertainties for observables that may be beyond the current experimental reach.
nucl-thnucl-ex7 citations
03
Interaction of accelerator neutrinos with energies up to 55 MeV with $^{127}$ I nuclei
Yu. S. Lutostansky🇷🇺 · A. N. Fazliakhmetov🇷🇺 · V. N. Tikhonov🇷🇺 · G. A. Koroteev🇷🇺 · N. A. Belogortseva🇷🇺 · N. V. Klochkova🇷🇺 · A. Yu. Lutostansky🇷🇺 · A. P. Osipenko🇷🇺 · E. Yu. Zemskov🇷🇺
The interaction of neutrinos with an energy of up to 55~MeV from the Spallation Neutron Source (SNS) accelerator with a perspective $^{127}$ I detector at the Oak Ridge National Laboratory (United States) has been studied. The resonance structure of the charge-exchange strength function $S (E)$ has been calculated taking into account high-lying resonances, and the effect of this structure on the cross section $σ (E)$ for the accelerator neutrino capture by the $^{127}$ I nucleus has been examined. The influence of the Gamow-Teller resonance GTR-1 and the second new higher resonance GTR-2 on the energy dependence of the cross section $σ (E)$ has been analyzed. The effect of the high-lying analog resonance AR-2 has also been taken into account for the first time. It has been found that the contributions of GTR-1 to the calculated cross section $σ (E)$ are from 60% to $\approx$ 80%, and GTR-2 about 12%, and AR-2 $\leq$ 10%, respectively. The contribution of high-lying resonances to the $(ν, n)$ and $(ν, 2 n)$ neutrino capture cross sections with neutron emission and the formation of the $^{126}$ I and $^{125}$ I isotopes, respectively, has been analyzed. The comparison of the cross sections for the interaction of accelerator neutrinos calculated by different methods with experimental data has shown coincidence at energies below the neutron separation threshold $E_{x} < S_{1 n}$ and strong discrepancy at higher energies, which is difficult to explain. A new measurement of cross sections at energies $E_{x} > S_{1 n}$ is needed.
nucl-thnucl-ex0 citations
04
Microscopic theory of the $γ$ decay of giant resonances in superfluid nuclei
W.-L. Lv · Y.-F. Niu · G. Colò
Recent advances in experiments have enabled the measurement of $γ$ -decay from giant and pygmy resonances to low-lying states, establishing this technique as a unique probe for nuclear structure. However, a microscopic description of $γ$ -decay to low-lying states in superfluid nuclei is still lacking. We develop the Skyrme quasiparticle vibration (QPVC) model to calculate $γ$ -decay widths between vibrational states. This model treats initial and final states as quasiparticle random phase approximation (QRPA) phonons and includes all the second-order diagrams for the interaction between the quasiparticles and the phonons, while consistently accounting for the polarization processes. The same Skyrme functional is employed for the ground state and the interaction vertices. As a timely application, the $γ$ -decay width from the giant dipole resonance to the $2_{1}^{+}$ state in $^{140}$ Ce is calculated, which has recently been measured at the high intensity $γ$ -ray source (HI $γ$ S). For the 4 Skyrme functionals we used, the total width of the collective dipole states in GDR region is 200-420 eV and the corresponding branching ratio is 0.75-1.20\%. The polarization effect, extracted microscopically, agrees in trend with the macroscopic Bohr-Mottelson formula.
nucl-th1 citation
05
Global polarization of $Λ$ hyperons and its sensitivity to equations of state in low-energy heavy-ion collisions
Cong Yi🇨🇳 · Shi Pu🇨🇳 · Long-Gang Pang🇨🇳 · Guang-You Qin🇨🇳 · Xin-Nian Wang🇨🇳
Significant global polarization of $Λ$ hyperons along the direction of the orbital angular momentum has been measured in non-central heavy-ion collisions where the equation of state (EOS) of the produced dense matter is expected to change from intermediate to low colliding energies. We study the sensitivity of the global $Λ$ polarization to EOS in heavy-ion collisions within the SMASH transport model. Among the three different EOS we considered, only the hadron resonance gas (HRG) describes the experimental data well at low colliding energies even when it is below the $Λ$ production threshold in nucleon-nucleon collisions. The polarization induced by thermal vorticity as a function of centrality, rapidity, and transverse momentum at $s_{N N} = 3$ GeV in Au+Au collisions is shown to agree well with the experimental data. Our study also indicates a possible peak in the global $Λ$ polarization around $s_{N N} = 2.4$ GeV in Au+Au collisions. Furthermore, we find that the rapidity and transverse momentum-dependent helicity polarization induced by thermal vorticity vanishes due to space-reversal symmetry.
nucl-th2 citations
06
Quark-Meson Coupling Model in Heavy-Ion Collision Simulations
Dae Ik Kim🇰🇷 · Chang-Hwan Lee🇰🇷 · Kyungil Kim🇰🇷 · Youngman Kim🇰🇷 · Sangyong Jeon🇨🇦 · Kazuo Tsushima🇧🇷
The quark-meson coupling (QMC) model incorporates quark degrees of freedom into the relativistic mean-field (RMF) framework, distinguishing it from traditional quantum hadrodynamics (QHD), which treats nucleons as point-like particles. In this work, we implement the QMC model within the DaeJeon Boltzmann-Uehling-Uhlenbeck (DJBUU) transport code to investigate its applicability to intermediate-energy heavy-ion collisions. We simulate \textsuperscript{197}Au+\textsuperscript{197}Au collisions at a beam energy of 400 A MeV using both QHD and QMC and find that both approaches yield comparable results for bulk observables such as transverse and directed flow, with good agreement with experimental data. To further assess the model performance, we study pion production in neutron-rich (\textsuperscript{132}Sn+\textsuperscript{124}Sn) and less neutron-rich (\textsuperscript{108}Sn+\textsuperscript{112}Sn) systems at 270 A MeV. In contrast to the QHD case, reproducing the observed pion yields and charge ratios within the QMC framework requires a slightly reduced density-dependent suppression in the in-medium $Δ$ production cross-section. These results demonstrate that the QMC model can be effectively integrated into transport simulations.
nucl-thPRC(2026)·1 citation
07
Quark-meson coupling model and heavy-ion collision
Dae Ik Kim🇰🇷 · Chang-Hwan Lee🇰🇷 · Kyungil Kim🇰🇷 · Youngman Kim🇰🇷 · Sangyong Jeon🇨🇦 · Kazuo Tsushima🇧🇷
We implement the quark-meson coupling model in Daejeon Boltzmann-Uehling-Uhlenbeck (DJBUU) transport model and perform Au+Au collision simulations at intermediate energies. Results are compared with simulations using a conventional quantum hadrodynamics model. Differences in the maximum density reached during the collisions are interpreted in terms of nuclear matter properties predicted by each model.
nucl-thEPJ Web Conf.(2026)·0 citations
08
Heavy-ion collision simulation with high performance computer
Dae Ik Kim🇰🇷 · Chang-Hwan Lee🇰🇷 · Youngman Kim🇰🇷 · Sangyong Jeon🇨🇦
Heavy-ion collision is an important tool to understand the dense nuclear matter properties. In order to understand the results of the heavy-ion collision experiments, both theoretical approaches to dense nuclear matter using effective models and the computer simulations with given theoretical models have been performed. Due to the complexity of the system and the theoretical framework, the heavy-ion collision simulations require heavy computer resources. In this talk, we report our recent preliminary work on the heavy-ion collision simulation using DaeJeon Boltzmann-Uehling-Uhlenbeck (DJBUU) and Sindong Quantum Molecular Dynamics (SQMD) model with high performance computers (HPC).
nucl-thJ.Subatomic Part.Cosmol.(2025)·0 citations
09
Study of radiative proton capture by the 7Be nucleus with the use of ab initio approaches
D. Rodkin · Yu. Tchuvilsky
A theoretical study of the 7Be(p,gamma)8B reaction in the astrophysical energy range with the use of ab initio methods is presented. The used approaches are No-Core Shell Model and Cluster Channels Orthogonal Functions Method. The scheme also contains elements of R-matrix theory and procedures for extrapolating various data obtained in ab initio computations. The developed approach as a whole allows one not only to calculate the astrophysical S-factor and all nuclear characteristics that determine its value, but also to evaluate the reliability of the obtained results and to identify the dominant reaction mechanisms against a background of insignificant ones.The high accuracy of the obtained results and has been demonstrated.
nucl-thastro-ph.SR0 citations
10
The East Lansing Model: a Bayesian uncertainty quantified optical potential for rare isotopes
K. Beyer · F. M. Nunes
The East Lansing Model is a global, uncertainty-quantified optical potential for neutron and proton projectiles, with a novel form for the neutron-proton asymmetry component, with the goal to improve extrapolations away from stability. Our Bayesian calibration relies on (n,n), (p,p) and (p,n) experimental data for angular distributions on spherical targets with mass $A \geq 40$ , and beam energies in the range $E = 10 - 100$ MeV. When considering the stable nuclei for which data is available, our results demonstrate that the inclusion of the $(p, n)$ data alone does not significantly change the parameterization. The additional information contained in (p,n) only becomes evident by introducing a new parameterization, one that gives the flexibility to encode neutron skins in the optical potential through an asymmetry dependent term. Finally, extrapolations of ELM toward the limits of stability (namely toward the proton and neutron driplines) leads to reduced uncertainties when compared to other global optical potentials in use.
nucl-thnucl-ex1 citation
11
From $α$ decay to cluster decay: an extreme case of transfer learning
Yinu Zhang · Zhiyi Li · Kele Li · Jiaxuan Zhong · Cenxi Yuan
When training data are limited, data-driven models are especially vulnerable to optimization-related fluctuations from random initialization and to sampling-induced bias from insufficient training data. We address both challenges with transfer learning (TL): deep neural networks (DNNs) are first pretrained on $α$ decay half-lives and then fine-tuned on a small cluster decay dataset. The pretraining stage provides a physically informed initialization that stabilizes optimization, while transferred global decay systematics regularize the fit and reduce sensitivity to training set composition. Despite extreme data sparsity, the resulting models accurately predict cluster decay half-lives for parent nuclei from $^{221}$ Fr to $^{242}$ Cm. We further quantify how initialization and sample selection affect predictive accuracy and robustness, demonstrating that TL enables stable and reliable learning in the small-sample regime.
nucl-thPRC(2026)·0 citations
12
Neural Quantum States in Non-Stabilizer Regimes: Benchmarks with Atomic Nuclei
James W. T. Keeble · Alessandro Lovato · Caroline E. P. Robin
As neural networks are known to efficiently represent classes of tensor-network states as well as volume-law-entangled states, identifying which properties determine the representational capabilities of neural quantum states (NQS) remains an open question. We construct NQS representations of ground states of medium-mass atomic nuclei, which typically exhibit significant entanglement and non-stabilizerness, to study their performance in relation to the quantum complexity of the target state. Leveraging a second-quantized formulation of NQS tailored for nuclear-physics applications, we perform calculations in active orbital spaces using a restricted Boltzmann machine (RBM), a prototypical NQS ansatz. For a fixed number of configurations, we find that states with larger non-stabilizerness are systematically harder to learn, as evidenced by reduced accuracy. This finding suggests that non-stabilizerness is a primary factor governing the compression and representational efficiency of RBMs in entangled regimes, and motivates extending these studies to more sophisticated network architectures.
nucl-thquant-ph2 citations

Affiliations

first authorsco-authorsvia INSPIRE