Nuclear Theory·nucl-th

Tuesday·May 26, 2026

13 papers—5 primary·8 cross-listed

01
[Submitted on 23 May 2026]
Intrinsic generation of angular momenta and entanglement in fission
B. Li · D. D. Zhang · D. Vretenar · T. Nikšić · P. W. Zhao · J. Meng
Nuclear time-dependent density functional theory is used to investigate spin generation and entanglement of fission fragments in spontaneous fission of $^{252}$ Cf, incorporating both axial and non-axial deformations. Axially symmetric fission trajectories enforce strict constraints: counter rotation (twisting mode) along the fission axis and equiprobable bending/wriggling modes perpendicular to it. Non-axial modes broaden the distributions of fission fragment spin projection on the fission axis, and allow for axial (tilting) collective rotations, which are forbidden on axially symmetric trajectories. Mutual information analysis reveals that axial-symmetry breaking reduces spin-spin correlations along the fission axis of symmetric cases, while perpendicular correlations remain more resilient. The effect of triaxial degrees of freedom on the opening angle distribution between the spins of the fission fragments is analyzed.
Comments:
28 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2605.24466 [pdf]
PRL(2026)·1 citation
02
[Submitted on 23 May 2026]
A unified classification-quantification framework for bubble-like nuclei within the extended quantum molecular dynamics model
Ge Ren · Chun-Wang Ma · Xi-Guang Cao · Kai-Xuan Cheng · Jie Pu
A systematic study of relaxed low-energy cluster configurations for all nuclides listed in the AME2020 database is performed within the extended quantum molecular dynamics (EQMD) framework, with frictional cooling enabling stable relaxation. A unified classification-quantification framework based on the dimensionless parameters $B H T U$ is established to characterize bubble-like nuclear morphologies. The factor $B$ , determined from the number of inflection points in the radial density profile, categorizes nuclei into droplet ( $B = 0$ ), bubble ( $B = 1$ ), and toroidal bubble ( $B = 2$ ). The parameter $H$ defines the degree of central density depletion, while $T$ and $U$ characterize the relative surface thickness and the relative size of the internal low-density region, respectively. Light nuclei are predominantly droplet-like with $B = 0$ , $H = 0$ , $T = 1$ , $U = 0$ . Most medium-mass nuclei have $B = 1$ , consistent with previous studies, especially in the vicinity of $^{40}$ Ca and the neutron-rich region, where nuclei show a pronounced central hollowing with large $H$ and $U$ values, identifying them as prime candidates for experimental searches for bubble structures. Toroidal bubble nuclei ( $B = 2$ ), emerging for $Z \approx 25$ and prevalent in heavy systems, display a local density minimum at intermediate radius together with a shell-like low-density region. Furthermore, bubble structures are found to be widespread in the superheavy region, in agreement with earlier studies. This parameter scheme not only reveals the morphological richness of nuclei but also establishes a predictive framework for exploring exotic nuclear shapes, thereby opening new avenues for future theoretical and experimental investigations.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2605.24676 [pdf]
0 citations
03
[Submitted on 24 May 2026]
Thermal Spin Polarization Driven by Nuclear Spin-Orbit Coupling in Neutron Star Pasta
Hiroyuki Tajima · Yuta Sekino · Hiroshi Funaki · Shota Kisaka · Nobutoshi Yasutake · Mamoru Matsuo
We discuss anomalous spin polarization on the surface of nuclear pasta in a neutron star, driven by a nuclear spin-orbit interaction. We present an effective two-band model of surface-localized neutrons near the nuclear pasta. The central point is the emergence of a Rashba-type spin-orbit hybridization generated by the neutron--nucleus spin-orbit force in the presence of the strong density gradient normal to the pasta surface. Starting from a single-particle Hamiltonian with a central potential and a standard nuclear spin-orbit interaction, we show that the surface spin polarization occurs due to the thermal inhomogeneity even in the absence of a magnetic field. Our study links neutron-star physics and solid-state spintronics and would contribute to understanding the interplay between spin dynamics and strong magnetic fields.
Comments:
7 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el)
arXiv:
2605.25067 [pdf]
0 citations
04
[Submitted on 25 May 2026]
A higher-harmonic observable for the chiral magnetic effect in heavy-ion collisions
Han-Sheng Li🇺🇸 · Yu-Shan Chang🇺🇸 · Yi Yang🇹🇼 · Fuqiang Wang🇺🇸
The chiral magnetic effect (CME) is a phenomenon in which electric charge is separated by a strong magnetic field from local domains of chirality imbalance in quantum chromodynamics. The CME-sensitive azimuthal correlator difference $Δ γ$ between opposite- and same-sign charged hadron pairs is designed to detect charge separation along the magnetic field, on average perpendicular to the reaction plane. However, the search for the CME is hindered by large background contributions to $Δ γ$ from particle correlations coupled with elliptic flow. In this work, we explore higher-harmonic components in differential $Δ γ (ϕ_{pair})$ as a function of the pair azimuthal angle. Such components could arise from event-by-event fluctuations of the magnetic fields throughout the collision zone, in both direction and magnitude. We show by using heavy-ion physics models that the hexadecapole component of $Δ γ (ϕ_{pair})$ is sensitive to the CME and insensitive to physics backgrounds. This could offer a unique observable for the CME that is robust against background contributions.
Comments:
8 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2605.25487 [pdf]
0 citations
05
[Submitted on 25 May 2026]
Multipole tomography of atomic nuclei with symmetry-conserved theories
X. Sun · J. Dobaczewski · W. Nazarewicz · H. Wibowo
To define the intrinsic reference frame and multipole moments of angular-momentum- $J$ -conserving many-body wave functions, we introduce two-body conditional probabilities of finding two nucleons at different positions in space. In this way, quadrupole deformations of states with $J \leq 1/2$ , which are not accessible via spectroscopic one-body quadrupole moments, can be characterized. We illustrate the method with nuclear density functional theory calculations for $J = 0$ states of $^{16}$ O and $^{20}$ Ne, the latter obtained by restoring rotational symmetry of prolate or oblate intrinsic configurations. We show that the two-body quadrupole shape characterizations differ from one-body moments obtained from broken-symmetry states.
Comments:
9 pages, 3 figures, submitted version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2605.26088 [pdf]
1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Intrinsic generation of angular momenta and entanglement in fission

A unified classification-quantification framework for bubble-like nuclei within the extended quantum molecular dynamics model

Thermal Spin Polarization Driven by Nuclear Spin-Orbit Coupling in Neutron Star Pasta

A higher-harmonic observable for the chiral magnetic effect in heavy-ion collisions

Multipole tomography of atomic nuclei with symmetry-conserved theories

Affiliations