Nuclear Theory·nucl-th

Thursday·July 30, 2026

11 papers—7 primary·4 cross-listed

01
Impacts of hexadecapole correlations in actinide nuclei
L. Lotina · K. Nomura · R. Rodr\'ıguez-Guzmán · L. M. Robledo
The impact of hexadecapole correlations on the low-energy spectroscopic properties of Th, U, and Pu nuclei, within the mass range $232 \leq A \leq 240$ , is studied systematically using the mapped $s d g$ -IBM model. Fermionic input is obtained via the quadrupole-hexadecapole constrained Hartree-Fock-Bogoliubov approximation, based on the parametrization D1S of the Gogny energy density functional. The $s d g$ -IBM Hamiltonian parameters are determined by mapping the quadrupole-hexadecapole fermionic mean-field potential energy surfaces onto the corresponding bosonic surfaces. The low-energy spectra and transition strengths, obtained via the diagonalization of the $s d g$ -IBM Hamiltonian, compare well with the available experimental data. It is shown that the effects of hexadecapole collectivity can be observed in high-spin yrast states with spins $J^{π} ⩾ 1 0^{+}$ . The mapped $s d g$ -IBM improves the excitation energies of those states, as compared with the simpler $s d$ -IBM model. The $s d g$ -IBM also improves the description of the $E 2$ transition strengths between high-spin yrast states and predicts strong $E 4$ transitions from nonyrast $4^{+}$ states to the $0^{+}$ ground state.
nucl-thnucl-exPRC(2026)·0 citations
02
Intruder-driven mirror energy differences between $^{29}$ Cl and $^{29}$ Mg studied with antisymmetrized molecular dynamics
Dae Ik Kim · Masaaki Kimura · Chang-Hwan Lee · Youngman Kim
To clarify the mirror energy differences (MEDs) of the proton-unbound nucleus $^{29}$ Cl and their microscopic origins, we investigate the low-lying states of the $^{29}$ Cl- $^{29}$ Mg mirror pair using antisymmetrized molecular dynamics. The calculation reasonably reproduces the normal and intruder states of $^{29}$ Mg, while suggesting alternative spin-parity assignments for $^{29}$ Cl. The $1/ 2^{+}$ and $3/ 2^{+}$ states are predicted to form a nearly degenerate ground-state doublet with a small MED because of their similar intrinsic structures. In contrast, the $3/ 2^{-}$ and $7/ 2^{-}$ intruder states exhibit large negative MEDs and are assigned to the observed resonances at approximately 500~keV and 1.1~MeV, respectively. Their large MEDs originate from the reduced Coulomb energies associated with the stronger deformation and spatially extended proton distributions in the intruder configurations.
nucl-th0 citations
03
Recent Progress in Ab-Initio Nuclear Theory for Precision Physics Searches in Muonic Atoms and Superallowed $β$ Decays
Simone Salvatore Li Muli · Michael Gennari
Precision tests of the Standard Model at low energy are increasingly limited by nuclear-structure theory rather than by experiment. We review two such cases: the two-photon-exchange correction to the Lamb shift in muonic atoms, and the \texorpdfstring{ $γ W$ }{gamma-W} box radiative correction to superallowed \texorpdfstring{ $β$ }{beta} decays. Although they probe different physics, both are governed by the same generalized hadronic tensor, so that the chiral effective field theory Hamiltonians and currents, Lanczos-based response methods, and Bayesian uncertainty quantification developed for one carry over directly to the other. We summarize recent ab initio progress in light nuclei and its impact on nuclear charge radii, on the helium isotope-shift puzzle, and on the extraction of \texorpdfstring{ $V_{u d}$ }{Vud} for the top-row CKM unitarity test, and state a future outlook.
nucl-thphysics.atom-ph0 citations
04
Structure of multi- $Λ$ hypernuclei with a Skyrme-type $ΛΛ$ interaction constrained by data on double- $Λ$ hypernuclei and neutron stars
Yusuke Tanimura · Chang Ho Hyun · Myung-Ki Cheoun
We investigate multi- $Λ$ hypernuclear systems with Skyrme-type $ΛΛ$ interactions constrained by the data on double- $Λ$ hypernuclei and neutron stars. The roles of the repulsive $p$ -wave and density-dependent terms in the $ΛΛ$ interaction are examined by considering the homogeneous hyperonic matter around the normal density and finite multi- $Λ$ hypernuclei within the spherical Hartree-Fock approach. In homogeneous matter, the $Λ$ chemical potential and corresponding $Λ$ drip point depend strongly on the repulsive $p$ -wave term, while the effect of density-dependent term is relatively weak in the density range relevant to finite nuclei. In the multi- $Λ$ hypernuclei built on doubly closed stable cores from light to heavy systems, $Λ$ radius, separation energy and single-particle structure show a clear dependence on the repulsive $p$ -wave interaction, and this dependence becomes stronger as the number of $Λ$ hyperons increases. A second and distinct effect appears near the $Λ$ drip line: when the last occupied $Λ$ orbit approaches the continuum, the repulsive $p$ -wave term shifts the state upward and can produce a weakly bound state with an extended radial distribution. As a result, $Λ$ radius can increase rapidly near the threshold. This threshold effect should be distinguished from the moderate enhancement of the dependence on $p$ -wave interaction with increasing number of $Λ$ hyperons. These results indicate that the multi- $Λ$ hypernuclei are particularly useful for isolating the role of $p$ -wave $ΛΛ$ interacion around the normal density, whereas the density-dependent term is expected to be more important interaction in the high-density domain relevant to neutron stars.
nucl-th0 citations
05
Critical net-proton number fluctuations with hydrodynamics
Rui-zhe Zhao · Shi Yin · Shanjin Wu · Lipei Du · Xiaofeng Luo · Wei-jie Fu
We compute the net-proton number fluctuations and their ratios $C_{2} / C_{1}$ , $C_{3} / C_{2}$ and $C_{4} / C_{2}$ on the hydrodynamic freeze-out hypersurface of particlization at nine collision energies, $s_{NN} = 7.7 - 200$ GeV, based on the fluctuations obtained from the functional renormalization group (fRG) approach, where both the regular and the critical fluctuations arising from the critical end point (CEP) are included. The transverse momentum and rapidity acceptance windows as same as the experimental measurements, the isospin randomization for the proton number fluctuations, and the global baryon conservation effect are implemented in the calculations. The results are also compared with the baseline results without critical fluctuations. It is found that for the low-order cumulants, e.g., $C_{2} / C_{1}$ the difference between the critical and non-critical results is small, while the difference increases with the increasing order of cumulants in the region of low collision energy. A non-monotonic dependence on the collision energy is observed in $C_{4} / C_{2}$ with critical fluctuations, which is absent in the results without critical fluctuations.
nucl-thhep-phnucl-ex1 citation
06
Spectroscopic basis for short-range three-nucleon forces
Josep Solà Cava · Arseniy A. Filin · Sven Heihoff · Henri Paul Huesmann · Evgeny Epelbaum
We introduce a spectroscopic basis for the subleading contact three-nucleon forces, which allows one to classify these interactions according to the total angular momentum and parity quantum numbers in a transparent way. Using this new basis, we explore the sensitivity of nucleon-deuteron observables to the three-nucleon short-range interactions. The low dimensionality of the variable-parameter space in the spectroscopic basis allows us to build a simple nucleon-deuteron scattering emulator using radial basis function interpolation. We perform exploratory fits of the subleading contact three-nucleon interactions and demonstrate that 9 of 13 low-energy constants can be reliably determined from elastic nucleon-deuteron scattering data.
nucl-thhep-phnucl-ex0 citations
07
Gamow shell model description of the hypernuclei
Alan Cruz Dassie🇫🇷 · Emiko Hiyama🇯🇵 · Nicolas Michel🇨🇳 · Marek Płoszajczak🇫🇷
Hypernuclear physics studies baryon interactions and the structure of exotic atomic nuclei, where strangeness plays a key role in dense matter. High-resolution $γ$ -ray spectroscopy (e.g., Hyperball at BNL/KEK) and upcoming facilities (J-PARC, JLab) have provided precise data on $p$ -shell hypernuclei, constraining $Y N$ potentials. We applied the Gamow shell model to $p$ -shell hypernuclei to systematically investigate the role of the $Λ N$ interaction and its components, and how it affects the mean field of nucleons. The Gamow shell model extends the standard shell model by replacing the harmonic oscillator basis with the Berggren ensemble, treating bound, resonant, and continuum states on equal footing. The effective Hamiltonian includes Woods-Saxon core potentials and two-body interactions (central, spin-orbit, tensor) optimized to experimental data. Our calculations reproduce and predict binding energies, excitation spectra, and densities for hypernuclei from $_{Λ}^{5} He$ to $_{Λ}^{16} O$ using the same $Λ N$ interaction. The tensor force significantly impacts excited-state splittings in bound systems, while its effect is suppressed in unbound cases due to the continuum coupling. The Gamow shell model provides a unified framework for hypernuclei, capturing the interplay between bound, resonant, and continuum states. This work lays the foundation for extending the model to heavier and multi-strange systems.
nucl-thPRC(2026)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Impacts of hexadecapole correlations in actinide nuclei

Intruder-driven mirror energy differences between 29Cl and 29Mg studied with antisymmetrized molecular dynamics

Recent Progress in Ab-Initio Nuclear Theory for Precision Physics Searches in Muonic Atoms and Superallowed β Decays

Structure of multi-Λ hypernuclei with a Skyrme-type ΛΛ interaction constrained by data on double-Λ hypernuclei and neutron stars

Critical net-proton number fluctuations with hydrodynamics

Spectroscopic basis for short-range three-nucleon forces

Gamow shell model description of the hypernuclei

Affiliations

Intruder-driven mirror energy differences between $^{29}$ Cl and $^{29}$ Mg studied with antisymmetrized molecular dynamics

Recent Progress in Ab-Initio Nuclear Theory for Precision Physics Searches in Muonic Atoms and Superallowed $β$ Decays

Structure of multi- $Λ$ hypernuclei with a Skyrme-type $ΛΛ$ interaction constrained by data on double- $Λ$ hypernuclei and neutron stars