Nuclear Theory·nucl-th

Thursday·July 3, 2025

14 papers—7 primary·7 cross-listed

01
[Submitted on 2 Jul 2025]
From bare two-nucleon interaction to nuclear matter and finite nuclei in a relativistic framework
Shihang Shen🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳 · Jie Meng🇨🇳 · Wei-Jiang Zou🇨🇳
Understanding nuclear forces, infinite nuclear matter, and finite nuclei within a unified framework has remained a central challenge in nuclear physics for decades. While most \textit{ab initio} studies employ nonrelativistic Schrödinger-equation frameworks, this work offers a relativistic perspective. Using a leading-order (LO) relativistic chiral interaction, we describe two-nucleon scattering via the Thompson equation, symmetric nuclear matter, and medium-mass nuclei (Ca, Ni, Zr, Sn) via the relativistic Brueckner-Hartree-Fock theory. Systematic uncertainties from regulator cutoffs and interaction parameters are analyzed. The empirical saturation region of nuclear matter is reproduced, and the binding energies and charge radii of medium-mass nuclei agree reasonably well with experimental data, significantly improving the ``Coester line". These results highlight that the relativistic approach, employing a leading-order chiral force with only four low-energy constants and no three-nucleon forces, can capture the most important dynamics and offer a complementary pathway to address longstanding challenges in nuclear \textit{ab initio} studies.
Comments:
15 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2507.01257 [pdf]
PRC(2026)·5 citations
02
[Submitted on 2 Jul 2025]
Impact of shape fluctuations on nuclear Schiff moments in heavy octupole-deformed nuclei
E. F. Zhou · J. M. Yao · J. Engel · J. Meng
Permanent electric dipole moments (EDMs) are among the most sensitive probes of CP violation beyond the Standard Model. In diamagnetic atoms, the EDM is determined primarily by the nuclear Schiff moment, whose uncertainty limits the interpretation of current and future EDM searches. For the experimentally most promising octupole-deformed nuclei, however, existing Schiff-moment calculations have largely relied on the rigid-shape approximation. Here we report the first fully microscopic beyond-mean-field study of Schiff moments in the heavy octupole-deformed nuclei $^{225}$ Ra, $^{229}$ Th, and $^{229}$ Pa, based on multireference covariant density functional theory (MR-CDFT) with symmetry restoration and quadrupole--octupole shape mixing. The results show that collective shape fluctuations reduce the Schiff moments by factors of two to four. Furthermore, the Schiff moments of $^{229}$ Th and $^{229}$ Pa are predicted to exceed that of $^{225}$ Ra by more than an order of magnitude, largely due to the near-degenerate parity doublets predicted by MR-CDFT. This work establishes a microscopic framework for calculating Schiff moments in heavy octupole-deformed nuclei, providing essential nuclear-structure input for ongoing and future EDM searches.
Comments:
6 pages, 2 figures and 1 table
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Atomic Physics (physics.atom-ph)
arXiv:
2507.01369 [pdf]
7 citations
03
[Submitted on 2 Jul 2025]
Pion properties in isospin-asymmetric nuclear matter using in-medium chiral perturbation theory
Kihong Kwon🇯🇵 · Yamato Suda🇯🇵 · Stephan Hübsch🇯🇵 · Daisuke Jido🇯🇵
We compute the density dependence of in-medium pion properties, such as mass, wave function renormalization, and decay constant in the correlation function approach, and how they change under the influence of isospin-asymmetric nuclear matter. To this end, we use in-medium chiral perturbation theory to compute the relevant Feynman diagrams up to two-loop diagrams. Our results show that the isospin asymmetry of the nuclear matter splits these quantities into three separate values, corresponding to the three pions. Consequently, the tendency of each in-medium pion mass, wave function renormalization, and decay constant is dependent on the density and the neutron-to-proton ratio $ρ_{n} / ρ_{p}$ of nuclear matter. We also derive an in-medium Gell-Mann--Oakes--Renner relation which is valid for isospin-asymmetric nuclear matter and investigate to what extent it holds within our calculations.
Comments:
23 pages, 3 figures, 4 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2507.01398 [pdf]
PRC(2025)·1 citation
04
[Submitted on 2 Jul 2025]
Bremsstrahlung emission accompanying ternary fission of \isotope[252]{Cf}
Sergei P. Maydanyuk (1, 2 and 3) · Ju-Jun Xie (1, 4 and 5) · Sergei O. Omelchenko (3) ((1) Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, Huizhou, China, (2) Wigner Research Centre for Physics, Budapest, Hungary, (3) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, Ukraine, (4) Heavy Ion Science and Technology Key Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China, (5) School of Nuclear Sciences and Technology, University of Chinese Academy of Sciences, Beijing, China)
\textbf{Background} In ternary fission, bremsstrahlung photons are emitted but those have never been studied yet theoretically and experimentally. In other reactions, bremsstrahlung has been studied for a long time. \textbf{Purpose} To clarify which new information about ternary fission can be obtained from study of bremsstrahlung emission accompanying the ternary fission of \isotope[252]{Cf}. \textbf{Methods} A new quantum model of emission of bremsstrahlung photons accompanying ternary fission of heavy nuclei with $α$ -particle as light charged particle is developed. The model takes into account geometry and dynamics of ternary fission. \textbf{Results} We present the theoretical results on the bremsstrahlung emission in the ternary fission of the \isotope[252]{Cf} nucleus. High sensitivity of the bremsstrahlung spectra is established by the model concerning to the following aspects of the ternary fission, and the theoretical calcualtions are in agreement with the preliminary experimental data. It is found that: (a) Photons are emitted with highest intensity in case of perpendicular motion of the $α$ \,particle concerning to fission axis; (b) Relative motion between heavy fragments reinforces significantly bremsstrahlung, leaving of $α$ -particle concerning to system of heavy fragments is less important; (c) Relative motion between two heavy fragments is faster, bremsstrahlung is more intensive. \textbf{Conclusions} Theoretical study of bremsstrahlung in ternary fission of the \isotope[252]{Cf} nucleus shows high sensitivity of bremsstrahlung spectra on the geometry and dynamics of ternary fission process. It is expected that new information can be obtained by the model when new experimental measurements of bremsstrahlung in ternary fission of the \isotope[252]{Cf} nucleus are available.
Comments:
14 pages, 7 captured figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex)
arXiv:
2507.01451 [pdf]
J.Phys.A(2026)·0 citations
05
[Submitted on 2 Jul 2025]
Probing the tetrahedral $α$ clusters in relativistic $^{16}$ O + $^{16}$ O collisions
Jin-Yu Hu🇨🇳 · Hao-jie Xu🇨🇳 · Xiaobao Wang🇨🇳 · Shi Pu🇨🇳
Relativistic $^{16}$ O + $^{16}$ O collisions probe the Quark-Gluon Plasma formed in small systems, while their collective phenomena illuminate the structure of $^{16}$ O. Recently, various configurations of $^{16}$ O from \textit{ab initio} calculations were implemented in heavy-ion models, such as the hydrodynamic model and a multiphase transport model (AMPT) to study cluster effects in relativistic $^{16}$ O + $^{16}$ O collisions. However, divergent predictions across configurations and models complicate interpretations. In this Letter, we isolate the impact of multi-nucleon correlations in relativistic $^{16}$ O + $^{16}$ O collisions while fixing the one-body density distribution of $^{16}$ O. Our results show that the normalized ratios $Norm (v_{2} {2} / v_{2} {4})$ and $Norm (v_{2} {2} / v_{3} {2})$ effectively probe the effects of one-body density (e.g., tetrahedral symmetry) and multi-nucleon correlations (e.g., $α$ clusters). These observables provide critical constraints for refining heavy-ion models, essential for investigating cluster configurations in light nuclei through relativistic heavy-ion collisions.
Comments:
6 page, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2507.01493 [pdf]
7 citations
06
[Submitted on 2 Jul 2025]
Ab Initio Complex Scaling and Similarity Renormalization Group for Continuum Properties of Nuclei
Osama Yaghi🇫🇷 · Guillaume Hupin🇫🇷 · Petr Navrátil🇨🇦
We introduce a novel \abinitio many-body method designed to compute the properties of nuclei in the continuum. This approach combines well-established techniques, namely the Complex Scaling (CS) and Similarity Renormalization Group (SRG) methods while employing the translationally invariant No-Core Shell Model (NCSM) as a few-body solver. We demonstrate that this combination effectively overcomes numerical limitations previously encountered in exploring continuum properties of light nuclei with standard many-body techniques, and at the same time makes less imperative the need for a continuous set of basis states for the continuum. To benchmark the method for applications in the many-body sector, we apply it to the \textsuperscript{4}He system, where semi-exact calculations within a finite basis are feasible. Our extrapolated results agree with exact calculations already published in the literature. We argue that different NN parametrizations of chiral EFT Hamiltonians will not permit to reproduce evaluated resonance properties of \textsuperscript{4}He. As an application, we showcase the case of the tetraneutron. This work enables the application of the method to $A > 4$ -mass systems, providing a reliable representation of the initial Hamiltonian and its continuum properties.
Comments:
7 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2507.01595 [pdf]
2 citations
07
[Submitted on 2 Jul 2025]
Transmutation of $^{16}$ O and $^{20}$ Ne at the Large Hadron Collider
Govert Nijs🇨🇭 · Wilke van der Schee🇨🇭
In July 2025 the Large Hadron Collider (LHC) will collide $^{16}$ O $^{16}$ O and $^{20}$ Ne $^{20}$ Ne isotopes in a quest to understand the physics of ultrarelativistic light ion collisions. One particular feature is that there are many smaller isotopes with the exact same charge over mass ratio that potentially can be produced and contaminate the beam composition. Using the Trajectum framework together with the GEMINI code we provide an estimate of the production cross-section and its consequences. A potential benefit could be the interesting measurement of the multiplicity and mean transverse momentum of $^{16}$ O $^{4}$ He collisions.
Comments:
3 pages, 3 figures and an appendix. v2: added figure 4. v3: added Ne-He, matches published version. The Trajectum code can be found at https://sites.google.com/view/govertnijs/trajectum , data points included in source
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2507.01659 [pdf]
PLB(2026)·7 citations
08
[Submitted on 1 Jul 2025] (cross-list from quant-ph)
Quantum Simulation of QED in Coulomb Gauge
Xiaojun Yao🇺🇸
A recent work considered quantum simulation of Quantum Electrodynamics on a lattice in the Coulomb gauge with gauge degrees of freedom represented in the occupation basis in momentum space. Here we consider the more efficient representation of the gauge degrees of freedom in field basis in position space and develop a quantum algorithm for real-time simulation. We show that the continuum Coulomb gauge Hamiltonian is equivalent to the temporal gauge Hamiltonian when acting on physical states consisting of fermion and transverse gauge fields. The Coulomb gauge Hamiltonian is discretized by using the Green's function of the discrete Laplacian operator under the Dirichlet boundary conditions. Both the continuum Coulomb gauge Hamiltonian and the discretized one proposed here guarantee that the unphysical longitudinal gauge fields are decoupled and commute with the corresponding Hamiltonian. Thus there is no need to impose any constraint. The local gauge field basis and the canonically conjugate variable basis are swapped efficiently using the quantum Fourier transform. We prove that the qubit cost to represent physical states and the gate count for real-time simulation scale polynomially with the lattice size, energy, time, accuracy, and Hamiltonian parameters in lattice units. The gate cost here for implementing the time evolution of the gauge field is reduced at least by a factor on the order of $1 0^{8}$ for modest lattice size and accuracy level compared with the previous work.
Comments:
32 pages; v2: published version, added a comparison of gate costs with previous work
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2507.01089 [pdf]
PRD(2026)·10 citations
09
[Submitted on 1 Jul 2025] (cross-list from astro-ph.HE)
Effect of symmetry energy on properties of rapidly rotating neutron stars and universal relations
Pion Sudarshan Yeasin🇵🇱 · Stefanos Tsiopelas🇵🇱 · Armen Sedrakian🇵🇱 · Jia-Jie Li🇨🇳
We investigated universal relations for compact stars rotating at the Keplerian (mass-shedding) limit, which is highly relevant for understanding the rapidly rotating objects formed in the aftermath of a neutron star-neutron star merger. Our analysis is based on a set of nucleonic equations of state (EoSs) featuring systematic variations in the symmetry energy slope parameter $L_{sym}$ and the isoscalar skewness parameter $Q_{sat}$ , varied within ranges that are broadly consistent with current laboratory and astrophysical constraints. The global observable properties of isolated maximally rotating stars are examined, focusing on the mass-radius relation, moment of inertia, quadrupole moment, and the Keplerian (maximum) rotation frequency, as well as their variations in the $L_{sym}$ - $Q_{sat}$ parameter space. Next, we demonstrate that, in the limit of Keplerian rotation, universal relations remain valid across the same set of EoSs characterized by varying $L_{sym}$ and $\Qsat$ . In particular, we present explicit results for the moment of inertia ( $I$ ) and quadrupole moment ( $Q$ ) as functions of compactness, as well as for the moment of inertia-quadrupole moment relation. All of these relations exhibit excellent universality, with deviations typically within a range from a few percent to 10\% across a wide range of parameters. Additionally, we verify for our set of EoSs that the universality of $I$ - $Q$ holds to higher accuracy (at the level of 1\%) in the slow-rotation approximation compared with the Kepler limit, where the relative error increases up to $≲ 10%$ . Our findings support the applicability of $I$ -Love- $Q$ -type universal relations in observational modeling of maximally rotating compact stars and the gravitational wave emitted by them.
Comments:
v2: 12 pages, 9 figures, journal version. v1: 11 pages, 8 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2507.01093 [pdf]
PRD(2025)·2 citations
10
[Submitted on 2 Jul 2025] (cross-list from astro-ph.HE)
Self-bound hybrid stars with strong phase transitions can relieve major compact star observation tensions
Chen Zhang🇨🇳 · Juan M. Z. Pretel🇧🇷 · Renxin Xu🇨🇳
Some recent pulsar observations cannot naturally fit into the conventional picture of neutron stars: the compact objects associated with HESS J1731-347 and XTE J1814-338 have too small radii in the low-mass regime, while the secondary component of GW190814 is too massive for neutron stars to be compatible with constraints from the GW170817 event. In this study, we demonstrate that all these anomalous observations and tensions, together with other conventional ones such as recent NICER observations of PSR J0740+6620, J0030+0451, and PSR J0437-4715, can be naturally explained simultaneously by a new general type of self-bound hybrid stars with large density discontinuities, and thus are radially stable in either the slow or rapid phase transition context. As a proof of concept, we use hybrid quark stars, inverted hybrid stars, and hybrid strangeon stars as benchmark examples to explicitly demonstrate the advantage and feasibility of self-bound hybrid stars with strong phase transitions in relieving all tensions related to compact stars' masses, radii, and tidal deformabilities.
Comments:
15 pages, 5 figures; PRD accepted version
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2507.01371 [pdf]
PRD(2026)·13 citations
11
[Submitted on 2 Jul 2025] (cross-list from nucl-ex)
Nuclear Physics Confronts Relativistic Collisions Of Isobars
Giuliano Giacalone🇩🇪 · Jiangyong Jia🇺🇸 · Vittorio Somà🇫🇷 · You Zhou🇩🇰 · Anatoli Afanasjev🇺🇸 · Massimiliano Alvioli🇮🇹 · Benjamin Bally🇫🇷 · Federica Capellino🇩🇪 · Jean-Paul Ebran🇫🇷 · Hannah Elfner🇩🇪 · Fernando G. Gardim🇧🇷 · André V. Giannini🇧🇷 and 34 other authors
High-energy collisions involving the $A = 96$ isobars $^{96}$ Zr and $^{96}$ Ru have been performed in 2018 at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) as a means to search for the chiral magnetic effect in QCD. This would manifest itself as specific deviations from unity in the ratio of observables taken between $^{96}$ Zr+ $^{96}$ Zr and $^{96}$ Ru+ $^{96}$ Ru collisions. Measurements of such ratios (released at the end of 2021) indeed reveal deviations from unity, but these are primarily caused by the two collided isobars having different radial profiles and intrinsic deformations. To make progress in understanding RHIC data, nuclear physicists across the energy spectrum gathered in Heidelberg in 2022 as part of an EMMI Rapid Reaction Task Force (RRTF) to address the following question. Does the combined effort of low-energy nuclear structure physics and high-energy heavy-ion physics enable us to understand the observations made in isobar collisions at RHIC?
Comments:
112 pages, 39figs; Report of the EMMI RRTF "Nuclear Physics Confronts Relativistic Collisions of Isobars" https://indico.gsi.de/event/14430/ https://indico.gsi.de/event/15627/
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2507.01454 [pdf]
26 citations
12
[Submitted on 2 Jul 2025] (cross-list from hep-ph)
Pentaquarks made of light quarks and their admixture to baryons
Nicholas Miesch🇺🇸 · Edward Shuryak🇺🇸 · Ismail Zahed🇺🇸
This paper is a continuation of our studies of multiquark hadrons. The anti-symmetrization of their wavefunctions required by Fermi statistics is nontivial, as it mixes orbital, color, spin and flavor structures. In our previous papers we developed a method to find them based on the representations of the permutation group, and derived the explicit wave functions for baryons excited to the first and second shells $(L = 1, 2)$ , tetraquarks $q q q ˉ q ˉ$ and hexaquarks ( $6 q$ ). Now we apply it to light pentaquarks ( $q q q q q ˉ$ ), in the S- and P-shells ( $L = 0, 1$ ). Using Jacobi coordinates, one can use the hyperdistance approximation in 12-dimensional space. We further address the issue of ``unquenching" of baryons, by considering their mixing with pentaquarks, via two channels, through the addition of $σ$ -like or $π$ -like $q ˉ q$ pairs. This mixing is central for understanding of the observed flavor asymmetry of the antiquark sea, the amount of orbital motion issue as well as other nucleon properties.
Comments:
In version 2 one missing reference is added
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2507.01861 [pdf]
PRD(2025)·2 citations
13
[Submitted on 2 Jul 2025] (cross-list from hep-ph)
Spin hydrodynamics -- recent developments
Samapan Bhadury🇵🇱 · Zbigniew Drogosz🇵🇱 · Wojciech Florkowski🇵🇱 · Valeriya Mykhaylova🇵🇱
After briefly touching on relativistic hydrodynamics, we provide a detailed description of recent developments in spin hydrodynamics. We discuss the theory of perfect spin hydrodynamics within two different approaches, which lead to identical generalized thermodynamic relations. We also indicate the applicability range of the theory, finding it compatible with the conditions existing in the late stages of heavy-ion collisions. Finally, we discuss the near-equilibrium dynamics.
Comments:
8 pages, Proceedings of 8th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP-2023). arXiv admin note: text overlap with arXiv:2411.19673
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2507.01864 [pdf]
J.Subatomic Part.Cosmol.(2025)·4 citations
14
[Submitted on 2 Jul 2025] (cross-list from hep-ex)
The Roper Resonance $N^{*} (1440)$ in Nucleon-Nucleon Collisions and the Issue of Dibaryons
Heinz Clement🇩🇪
In many reactions leading to excitations of the nucleon the Roper resonance $N^{*} (1440)$ can be sensed only by complex partial-wave analyses. In nucleon-nucleon collisions the isoscalar single-pion production as well as specific two-pion production channels present the Roper excitation free of competing resonance processes at a mass of 1370 MeV and a width of 150 MeV. A detailed analysis points to the formation of $N^{*} (1440) N$ dibaryonic systems during the nucleon-nucleon collision process similar to what is known from the $Δ (1232) N$ threshold.
Subjects:
High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2507.01937 [pdf]
Acta Phys.Polon.B(2026)·1 citation

Affiliations

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