Nuclear Theory·nucl-th

Tuesday·June 24, 2025

15 papers—8 primary·7 cross-listed

01
[Submitted on 19 Jun 2025]
Causality of polarizeable dissipative fluids from Lagrangian hydrodynamics
David Montenegro🇷🇺 · Giorgio Torrieri🇧🇷
We perform a causality analysis on the dispersion relation of hydrodynamics with spin well as shear and bulk viscosity, including the relaxation times for all these quantities. We find that the interplay of the three relaxational scales, for shear and bulk viscosity as well as polarization, leads to non-trivial effects on the dispersion relation. Unexpectedly, the presence of polarization leads to lower effective viscosity and a longer relaxation time, and the presence of viscosity leads to lower limits as well as upper ones on the group velocity and constraints relating polarization to viscosity relaxation times. We conclude with a qualitative discussion on how these results impact phenomenology, specifically the low effective viscosity in strongly interacting matter as well as shear-vorticity coupling.
Comments:
Version Accepted for publication,Phys.Rev.D
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th)
arXiv:
2506.17327 [pdf]
PRD(2025)·3 citations
02
[Submitted on 21 Jun 2025]
Exploring the neutron-star matter properties via the deformed nuclear reactions
Yuan-Qing Guo🇨🇳 · Ya-Peng Zhang🇨🇳 · Zhao-Qing Feng🇨🇳
Within the framework of Lanzhou quantum molecular dynamics transport model, the correlation of initial deformation and isospin diffusion is systematically investigated in collisions of $^{238}$ U + $^{238}$ U. The impacts of the collision centrality, symmetry energy and initial configuration on the collective flows, neutron/proton and $π^{-} / π^{+}$ ratios have been systematically investigated. It is found that the broader neutron-rich region is formed in the body-body collisions in comparison with the ones in the tip-tip collisions. The neutron-star matter might be created in the density region of 0.2-0.5 $ρ_{0}$ (the normal nuclear density $ρ_{0}$ =0.165 fm $^{- 3}$ ) formed in the $^{238}$ U + $^{238}$ U reaction at the incident energy of 500 MeV/nucleon. The elliptic flows of protons are related to the incident energy, collision centrality, symmetry energy and collision orientation. The hard symmetry energy enables the larger free neutron/proton ratio at the beam energy of 500 MeV/nucleon. However, the neutron/proton and $π^{-} / π^{+}$ ratios in the density regime of $1.2 \leq ρ / ρ_{0} \leq 1.8$ are enhanced by the soft symmetry energy with the slope parameter of L=42 MeV.
Comments:
7 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.17571 [pdf]
PRC(2026)·0 citations
03
[Submitted on 21 Jun 2025]
Relations between spin observables of the reactions $dd \to n p d$ and $p d \to p d$ in impulse approximation
Yu.N. Uzikov🇷🇺
It is shown that the vector and tensor analyzing powers $A_{y}$ , $A_{y y}$ and also double spin correlation coefficients $C_{y, y}$ , $C_{y y, y}$ of the reaction $dd \to n + p + d$ in impulse approximation are linearly connected to corresponding observables of the $p d$ - elastic scattering. Obtained relations are necessary for motivation of the polarization experiments for the first phase of the SPD NICA project and for analysis of expected data.
Comments:
9 pages, 1 figure Submitted to Physics of Elementary Particles and Atomic Nuclei, Letters
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.17799 [pdf]
Phys.Part.Nucl.Lett.(2025)·2 citations
04
[Submitted on 22 Jun 2025]
Investigation of the neutron-proton effective mass splitting via heavy ion collisions: Constraints and Implications
Junping Yang · Meiqi Sun · Ying Cui · Yangyang Liu · Zhuxia Li · Kai Zhao · Yingxun Zhang
The neutron-proton effective mass splitting ( $Δ m_{n p}^{*}$ ) is investigated through analyses of heavy-ion collisions using the improved quantum molecular dynamics (ImQMD) model with both standard and extended Skyrme interactions. By uncovering the strong correlation between the slope of the neutron-to-proton yield ratio with respect to the kinetic energy (i.e., $S_{n / p}$ ) and $Δ m_{n p}^{*}$ , we reveal that the constraints of the neutron-proton effective mass splitting via heavy ion collisions depend on the kinetic energy region of the emitted nucleons. At low kinetic energies, the data favor $m_{n}^{*} > m_{p}^{*}$ which is consistent with the nucleon-nucleus scattering analysis, while at high kinetic energies, they favor $m_{n}^{*} < m_{p}^{*}$ . Our findings partly resolve the longstanding discrepancy in the constraints of neutron-proton effective mass splitting with heavy ion collisions and nucleon-nucleus scattering, and significantly advance the understanding of nucleon effective mass splitting through heavy ion collisions.
Comments:
7 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2506.17973 [pdf]
PRC(2025)·4 citations
05
[Submitted on 22 Jun 2025]
Towards Quantum Simulation of Rotating Nuclei using Quantum Variational Algorithms
Dhritimalya Roy🇮🇳 · Somnath Nag🇮🇳
Quantum variational algorithms (QVAs) are increasingly potent tools for simulating quantum many-body systems on noisy intermediate-scale quantum (NISQ) devices. This work examines the application of the Variational Quantum Eigensolver (VQE) to four progressively complex models based on the cranked Nilsson-Strutinsky (CNS) framework. By incorporating single-particle spacings, pairing correlations, and rotational cranking terms, we evaluate VQE performance against exact diagonalization (ED) benchmarks. We provide a systematic benchmarking of VQE across a hierarchy of CNS-inspired Hamiltonians, explicitly identifying where hardware-efficient ansatz succeed and fail, and introducing quantum information diagnostics, the entanglement spectrum and Quantum Fisher Information, as novel probes of the pairing-rotation. Our results demonstrate that with a properly optimised multi-restart warm-starting strategy, VQE achieves near-machine-precision convergence ( $∣Δ E ∣ < 1 0^{- 4}$ ) across the full cranking frequency range $ω \in [0, 1.2]$ and we confirm that the same strategy reproduces an established $^{6}$ He shell-model pairing benchmark, demonstrating that the RealAmplitudes ansatz is expressively sufficient for this problem class. The entanglement spectrum confirms the product-state character of the exact ground state throughout the pairing-rotation transition, while the Quantum Fisher Information identifies a finite-size precursor to the critical pair-breaking frequency. These results establish a systematic methodological baseline and provide a reproducible framework for the nuclear physics community.
Comments:
Accepted for publication in EPJP
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Quantum Physics (quant-ph)
arXiv:
2506.18059 [pdf]
Eur.Phys.J.Plus(2026)·0 citations
06
[Submitted on 23 Jun 2025]
Nuclear and neutron matter in the relativistic Brueckner-Hartree-Fock theory with next-to-leading order covariant chiral nuclear force
Wei-Jiang Zou🇨🇳 · Yi-Long Yang🇨🇳 · Jun-Xu Lu🇨🇳 · Peng-Wei Zhao🇨🇳 · Li-Sheng Geng🇨🇳 · Jie Meng🇨🇳
The symmetric nuclear matter and pure neutron matter are investigated by the relativistic Brueckner-Hartree-Fock (RBHF) theory with the covariant chiral nuclear forces up to the next-to-leading order~(NLO). A fitting scheme to ensure the naturalness of the low-energy constants is proposed, which plays a crucial role in the proper description of nuclear matter. With a momentum cutoff $Λ = 590$ MeV, the empirical saturation energy and density, as well as the incompressibility coefficient at the saturation density are reproduced well. The EoSs show less dependence on the momentum cutoff and become softer at densities above saturation density, in comparison with the previous leading order results. Given the good description for the saturation properties of nuclear matter, the present work encourages future studies of the finite nuclei in the framework of the RBHF theory with the NLO covariant chiral nuclear forces.
Comments:
22 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2506.18519 [pdf]
PRC(2026)·5 citations
07
[Submitted on 23 Jun 2025]
Correlation between particle spectra and elliptic flow
Tribhuban Parida🇮🇳 · Rupam Samanta🇵🇱 · Jean-Yves Ollitrault🇫🇷
We introduce a new observable to probe the collective nature of the radial expansion of the quark-gluon plasma. This observable, dubbed $v_{02} (p_{T})$ , represents the correlation of the spectrum with elliptic flow, in the same way as the recently measured $v_{0} (p_{T})$ represents the correlation of the spectrum with the transverse momentum per particle. The advantage of $v_{02} (p_{T})$ over $v_{0} (p_{T})$ is that it is measured using a three-particle cumulant, as opposed to a pair correlation, which significantly reduces the sensitivity to nonflow effects. We predict non-trivial differences between $v_{02} (p_{T})$ and $v_{0} (p_{T})$ in semi-central Pb+Pb collisions at the Large Hadron Collider (LHC) on the basis of hydrodynamic simulations. A hint of these differences can be seen in the modification of $p_{T}$ spectra observed by ALICE in event-shape-engineered events.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2506.18690 [pdf]
PLB(2025)·5 citations
08
[Submitted on 23 Jun 2025]
Nuclear $β$ -decay half-lives within the subtracted second random-phase approximation
Danilo Gambacurta🇮🇹 · Marcella Grasso🇫🇷
We employ, within the framework of Skyrme energy-density functional theory, the subtracted second random-phase approximation, recently developed for charge-exchange excitations, to compute $β$ -decay half-lives in four nuclei, $^{24}$ O, $^{34}$ Si, $^{78}$ Ni, and $^{132}$ Sn. Following our recent results on the description of the Gamow-Teller strength, we proceed coherently in the present work by computing $β$ -decay half-lives using the bare value of the axial-vector coupling constant $g_{A}$ . Half-lives are thus obtained, within the allowed Gamow-Teller approximation, without the use of any ad hoc quenching factors. A genuine quenching is indeed microscopically introduced in our model owing to the correlations induced by the coupling of one-particle one-hole configurations with two-particle two-hole ones. The role of the so-called $J^{2}$ terms is also studied. By comparing our results with experimental data, we show a general improvement of $β$ -decay half-lives with respect to results obtained within the commonly used Random Phase Approximation (RPA). The inclusion of the two-particle two-hole configurations produces a more fragmented and richer spectrum within the $β$ -window, resulting in lower $β$ half-lives with respect to the RPA ones.
Comments:
To appear in The European Physical Journal A
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.18849 [pdf]
EPJA(2025)·1 citation
09
[Submitted on 20 Jun 2025] (cross-list from hep-ph)
Nuclear Cold QCD: Review and Future Strategy
F. Arleo🇫🇷 · P. Caucal🇫🇷 · A. Deshpande🇺🇸 · J. M. Durham🇺🇸 · G. M. Innocenti🇺🇸 · J. Jalilian-Marian🇺🇸 · A. Kusina🇵🇱 · M. X. Liu🇺🇸 · Y. Mehtar-Tani🇺🇸 · C.-J. Naïm🇺🇸 · H. Paukkunen🇫🇮 · S. Platchkov🇫🇷 and 3 other authors
This review examines data from hadron-nucleus collisions, primarily focusing on hard processes like Drell-Yan, heavy flavor and quarkonium production. It highlights observed modifications of particle yields as functions of momentum and rapidity, aiming to clarify the underlying QCD effects in cold nuclear matter (CNM). The paper outlines strategies for future experiments, including the Electron-Ion Collider (EIC), to distinguish between these effects. Key questions address the universality of suppression mechanisms and the role of non-perturbative physics, providing a road map for upcoming nuclear data.
Comments:
43 pages, 20 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2506.17454 [pdf]
PRC(2026)·15 citations
10
[Submitted on 21 Jun 2025] (cross-list from astro-ph.HE)
Three-dimensional equation of state extension of quark matter in Fermi-liquid theory
Zhenyu Zhu🇺🇸 · Shuai Zha🇨🇳 · Sophia Han🇨🇳
The cold, dense matter equation of state (EoS) determines crucial global properties of neutron stars (NSs), including the mass, radius and tidal deformability. However, a one-dimensional (1D), cold, and $β$ -equilibrated EoS is insufficient to fully describe the interactions or capture the dynamical processes of dense matter as realized in binary neutron star (BNS) mergers or core-collapse supernovae (CCSNe), where thermal and out-of-equilibrium effects play important roles. We develop a method to self-consistently extend a 1D cold and $β$ -equilibrated EoS of quark matter to a full three-dimensional (3D) version, accounting for density, temperature, and electron fraction dependencies, within the framework of Fermi-liquid theory (FLT), incorporating both thermal and out-of-equilibrium contributions. We compare our FLT-extended EoS with the original bag model and find that our approach successfully reproduces the contributions of thermal and compositional dependencies of the 3D EoS. Furthermore, we construct a 3D EoS with a first-order phase transition (PT) by matching our 3D FLT-extended quark matter EoS to the hadronic DD2 EoS under Maxwell construction, and test it through the GRHD simulations of the TOV-star and CCSN explosion. Both simulations produce consistent results with previous studies, demonstrating the effectiveness and robustness of our 3D EoS construction with PT.
Comments:
17 pages, 10 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2506.17569 [pdf]
PRD(2025)·5 citations
11
[Submitted on 21 Jun 2025] (cross-list from nucl-ex)
Imaging nuclear shape through anisotropic and radial flow in high-energy heavy-ion collisions
STAR Collaboration
Most atomic nuclei exhibit ellipsoidal shapes characterized by quadrupole deformation $β_{2}$ and triaxiality $γ$ , and sometimes even a pear-like octupole deformation $β_{3}$ . The STAR experiment introduced a new "imaging-by-smashing" technique [arXiv:2401.06625, arXiv:2501.16071] to image the nuclear global shape by colliding nuclei at ultra-relativistic speeds and analyzing outgoing debris. Features of nuclear shape manifest in collective observables like anisotropic flow $v_{n}$ and radial flow via mean transverse momentum $[p_{T}]$ . We present new measurements of the variances of $v_{n}$ ( $n = 2$ , 3, and 4) and $[p_{T}]$ , and the covariance of $v_{n}^{2}$ with $[p_{T}]$ , in collisions of highly deformed $^{238}$ U and nearly spherical $^{197}$ Au. Ratios of these observables between the two systems effectively suppress common final-state effects, isolating the strong impact of uranium's deformation. By comparing results with state-of-the-art hydrodynamic model calculations, we extract $β_{2 U}$ and $γ_{U}$ values consistent with those deduced from low-energy nuclear structure measurements. Measurements of $v_{3}$ and its correlation with $[p_{T}]$ also provide the first experimental suggestion of a possible octupole deformation for $^{238}$ U. These findings provide significant support for using high-energy collisions to explore nuclear shapes on femtosecond timescales, with implications for both nuclear structure and quark-gluon plasma studies.
Comments:
20 pages, 29 figures + an appendix
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.17785 [pdf]
Rept.Prog.Phys.(2025)·40 citations
12
[Submitted on 23 Jun 2025] (cross-list from hep-ph)
Existence of nuclear modifications on longitudinal-transverse structure-function ratio
S. Kumano🇨🇳
It has been assumed that nuclear modification does not exist in the longitudinal-transverse structure-function ratio $R_{N} = F_{L}^{N} / (2 x F_{1}^{N})$ in lepton deep inelastic scattering. This assumption is widely used in obtaining structure functions of the "nucleon" from nuclear data such as the deuteron ones. However, nuclear modifications do exist theoretically at least in medium- and large- $x$ regions because nucleons in a nucleus move in any direction, which is not necessarily the longitudinal direction of the virtual-photon or weak-boson momentum in lepton scattering. Because of this transverse motion, the nucleon's transverse and longitudinal structure functions should mix with each other in nuclei with the mixture probability proportional to the nucleon's transverse momentum squared $p_{T}^{2} / Q^{2}$ . In this work, numerical results are explicitly shown regarding such nuclear modifications in the deuteron. These nuclear modifications are important for determining precise structure functions of the nucleon. Furthermore, modifications of $R_{N}$ should be investigated also at small $x$ by the future electron-ion collider to find interesting gluon dynamics in nuclei. Hopefully, this nuclear effect of $R_{N}$ could be found by future experimental measurements at lepton accelerator facilities.
Comments:
6 pages, 3 figures, Physical Review C in press
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2506.18305 [pdf]
PRC(2026)·2 citations
13
[Submitted on 23 Jun 2025] (cross-list from quant-ph)
Systematic improvement of the quantum approximate optimisation ansatz for combinatorial optimisation using quantum subspace expansion
Yann Beaujeault-Taudière
The quantum approximate optimisation ansatz (QAOA) is one of the flagship algorithms used to tackle combinatorial optimisation on graphs problems using a quantum computer, and is considered a strong candidate for early fault-tolerant advantage. In this work, I study the enhancement of the QAOA with a generator coordinate method (GCM), and achieve systematic performances improvements in the approximation ratio and fidelity for the maximal independent set on Erdös-Rényi graphs. The cost-to-solution of the present method and the QAOA are compared by analysing the number of logical CNOT and $T$ gates required for either algorithm. Extrapolating on the numerical results obtained, it is estimated that for this specific problem and setup, the approach surpasses QAOA for graphs of size greater than 75 using as little as eight trial states. The potential of the method for other combinatorial optimisation problems is briefly discussed.
Comments:
13 pages, 10 figures. Remarks/comments welcome
Subjects:
Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
arXiv:
2506.18594 [pdf]
0 citations
14
[Submitted on 23 Jun 2025] (cross-list from gr-qc)
$g$ -mode oscillations of dark matter admixed neutron stars
Swarnim Shirke🇮🇳 · Debarati Chatterjee🇮🇳 · Prashanth Jaikumar🇺🇸
We investigate $g$ -mode oscillations in dark matter admixed neutron stars employing a relativistic mean field model to describe hadronic matter and a model for self-interacting fermionic dark matter motivated by the neutron decay anomaly. Following the construction of such admixed configurations, we derive the equilibrium and adiabatic speeds of sound therein, leading to a computation of the star's $g$ -mode spectrum in the Cowling approximation. In particular, we explore the effect of dark matter self-interaction, the nucleon effective mass and dark matter fraction on the principal $g$ -mode frequency, and its first overtone. We show that the effect on $g$ -mode frequency depends predominantly on the dark matter fraction, and demonstrate an equation of state-independent constraint for the latter. Prospects of identifying the presence of dark matter in neutron stars using $g$ -mode are discussed.
Comments:
13 pages, 10 figures, 3 tables. Accepted version. Accepted for publication in MNRAS
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2506.18892 [pdf]
MNRAS(2025)·9 citations
15
[Submitted on 23 Jun 2025] (cross-list from hep-ph)
Relativistic corrections to exclusive photoproduction of Quarkonia near-threshold
Sarah K. Blask🇺🇸 · Sean Fleming🇺🇸 · Thomas Mehen🇺🇸 · Jyotirmoy Roy🇺🇸 · Iain W. Stewart🇺🇸 · Fanyi Zhao🇺🇸
Non-relativistic QCD (NRQCD) is used to calculate the relativistic correction to the amplitude for exclusive photoproduction of vector Quarkonia in the near-threshold region within the generalized parton distribution (GPD) framework. The relativistic corrections are found to be large for $J / ψ$ , and lead to a breakdown of the GPD moment expansion near threshold. Cross-sections for both $J / ψ$ and $Υ$ are calculated with the former being compared to the data. We also demonstrate the presence of endpoint divergences for the relativistic correction away from the near-threshold regime.
Comments:
17 pages, 7 figures, additional calculations and discussion added, new figures added, typographical errors fixed
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.18905 [pdf]
JHEP(2026)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE