Nuclear Theory·nucl-th

Tuesday·April 16, 2024

14 papers—9 primary·5 cross-listed

01
[Submitted on 13 Apr 2024]
Correlation between the charge radii difference in mirror partner nuclei and the symmetry energy slope
Xiao-Rong Ma · Shuai Sun · Rong An · Li-Gang Cao
A correlation between the charge radii difference of mirror partner nuclei $Δ R_{ch}$ and the slope parameter $L$ of symmetry energy has been built to ascertain the equation of state of isospin asymmetric nuclear matter. In this work, the influences of pairing correlations and isoscalar compression modulus on the $Δ R_{ch}$ are systematically investigated based on the Skyrme energy density functional theory. The calculated results suggest that the linear correlation between $Δ R_{ch}$ and $L$ is decreased by the surface pairing correlations. The slope parameter deduced from the difference of charge radii of mirror-pair nuclei $^{32}$ Ar- $^{32}$ Si, $^{36}$ Ca- $^{36}$ S, $^{38}$ Ca- $^{38}$ Ar, and $^{54}$ Ni- $^{54}$ Fe falls into the range of $L$ =42.57-50.64 MeV, that is, the rather soft equation of state of asymmetric nuclear matter. Besides, the range of the slope parameter can also be influenced by the effective forces classified by various isoscalar incompressibility coefficients.
Comments:
8 pages, 4 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2404.08982 [pdf]
CPC(2024)·6 citations
02
[Submitted on 14 Apr 2024]
Spin entanglement of multinucleons: experimental prospects
Dong Bai · Zhongzhou Ren
Multiprotons and multineutrons are among the most exotic and mysterious things ever produced on earth. They provide an exceptional opportunity to understand nuclear forces and nuclear dynamics at extreme conditions, as well as neutron stars in the heaven. Quantum entanglement, referred to as ``spooky action at a distance'' by Einstein, is a ubiquitous yet deep property of quantum systems. It not only occupies a central position in quantum information science but also is investigated intensively in high energy physics, condensed matter physics, and quantum gravity. In comparison, the study of nuclear entanglement is still in infancy, and the entanglement properties of multiprotons and multineutrons in free space are generally unknown. Here, we study the crucial problem of how to measure spin entanglement of these multinucleons in nuclear experiments, with special emphases on two- and three-nucleon states. These findings open a freshly new direction for the multinucleon research. They are also useful for understanding entanglement properties of other exotic nuclear objects.
Comments:
6 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2404.09116 [pdf]
8 citations
03
[Submitted on 15 Apr 2024]
Historical introduction to ultra peripheral collisions
C.A. Bertulani🇺🇸
This is a brief history of photons, both soft and hard, real and virtual. About 150-100 years ago, Maxwell and Einstein discovered intriguing properties of electromagnetic fields and how to understand them both macroscopically and microscopically. Decades later, physicists developed the theory of renormalized quantum electrodynamics (QED), an incredibly accurate theory describing interactions of photons and other particles. Photons are used everywhere in academia and technological devices, from supermarket lasers and doors to academic studies in atomic, nuclear, and particle physics. In this article, I attempt to convey how the field of relativistic heavy ions rediscovered ultra-peripheral collisions (UPC) as a source of intense, almost real photons, and how it permits the study of a plethora of phenomena in the aforementioned academic fields. These phenomena are not always accessible by other means.
Comments:
13 pages, 15 figures, contribution to the International Workshop on the Physics of Ultra Peripheral Collisions (UPC2023), Playa del Carmen, Mexico, (October 2023)
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2404.09505 [pdf]
Phys.Proc.UPC(2024)·2 citations
04
[Submitted on 15 Apr 2024]
Bayesian inference of neutron-skin thickness and neutron-star observables based on effective nuclear interactions
Jia Zhou🇨🇳 · Jun Xu🇨🇳
We have obtained the constraints on the density dependence of the symmetry energy from neutron-skin thickness data by parity-violating electron scatterings and neutron-star observables using a Bayesian approach, based on the standard Skyrme-Hartree-Fock (SHF) model and its extension as well as the relativistic mean-field (RMF) model. While the neutron-skin thickness data (neutron-star observables) mostly constrain the symmetry energy at subsaturation (suprasaturation) densities, they may more or less constrain the behavior of the symmetry energy at suprasaturation (subsaturation) densities, depending on the energy-density functional form. Besides showing the final posterior density dependence of the symmetry energy, we also compare the slope parameters of the symmetry energy at 0.10 fm $^{- 3}$ as well as the values of the symmetry energy at twice saturation density from three effective nuclear interactions. The present work serves as a comparison study based on relativistic and non-relativistic energy-density functionals, for constraining the nuclear symmetry energy from low to high densities using a Bayesian approach.
Comments:
10 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)
arXiv:
2404.09511 [pdf]
SCPMA(2024)·12 citations
05
[Submitted on 15 Apr 2024]
Global prediction of nuclear charge density distributions using deep neural network
Tian Shuai Shang · Hui Hui Xie · Jian Li · Haozhao Liang
A deep neural network (DNN) has been developed to generate the distributions of nuclear charge density, utilizing the training data from the relativistic density functional theory and incorporating available experimental charge radii of 1014 nuclei into the loss function. The DNN achieved a root-mean-square (rms) deviation of 0.0193 fm for charge radii on its validation set. Furthermore, the DNN can improve the description in both the tail and central regions of the charge density, enhancing agreement with experimental findings. The model's predictive capability has been further validated by its agreement with recent experimental data on charge radii. Finally, this refined model is employed to predict the charge density distributions in a wider range of nuclide chart, and the parameterized charge densities, charge radii, and higher-order moments of charge density distributions are given, providing a robust reference for future experimental investigations.
Comments:
11 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2404.09558 [pdf]
PRC(2024)·30 citations
06
[Submitted on 15 Apr 2024]
1/2 $^{-}$ $α$ cluster resonances of $^{13}$ C studied by the analytic continuation in the coupling constant
Seungheon Shin · Masaaki Kimura · Bo Zhou · Qing Zhao
The 1/2 $^{-}$ resonant states in $^{13} C$ are investigated to search for the Hoyle-analog state. In order to treat the resonance states located around the 3 $α + n$ threshold, the analytic continuation in the coupling constant (ACCC) has been combined with the real-time evolution method (REM). The properties of the 1/2 $^{-}$ resonance states such as the radii and monopole transition probabilities are calculated. We show the 1/2 $_{3}^{-}$ and 1/2 $_{4}^{-}$ states are well-developed $α$ cluster states, and the 1/2 $_{4}^{-}$ state is a candidate of the Hoyle-analog state.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2404.09712 [pdf]
PRC(2026)·1 citation
07
[Submitted on 12 Apr 2024]
Nuclear cluster structure effect in $^{16}$ O+ $^{16}$ O collisions at the top RHIC energy
Xin-Li Zhao🇨🇳 · You Zhou🇺🇸 · Zi-Wei Lin🇩🇰 · Chao Zhang🇨🇳 · Guo-Liang Ma🇨🇳
Using the improved string-melting version of a Multi-Phase Transport model, we investigated the impact of nuclear geometry of $^{16}$ O on anisotropic flows in O+O collisions at $s_{NN} = 200$ GeV. To evaluate the influence of nuclear structure and potential alpha clustering, we implemented four candidate configurations: Woods-Saxon, tetrahedron, square, and Nuclear Lattice Effective Field Theory. Initial-state geometry is quantified via the eccentricity cumulant ratio $ε_{2} {4} / ε_{2} {2}$ , which provides a robust and evolution-independent measure sensitive to configuration differences. The model reproduces $v_{2} (p_{T})$ at low $p_{T}$ and $v_{3} (p_{T})$ across the full $p_{T}$ range, with integrated $v_{2} {2}$ and $v_{3} {2}$ matching the STAR data, demonstrating that transport dynamics captures the essential collectivity in this intermediate-size system. These findings establish a baseline for extending nuclear-structure studies in O+O collisions to other energies and differential observables within a unified transport model framework.
Comments:
An improved AMPT-SM model has been adopted, which is detailed in the new appendix
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2404.09780 [pdf]
PLB(2026)·23 citations
08
[Submitted on 15 Apr 2024]
The NICER data and a $σ$ -field dependent stiffness of the hadronic equation of state
E. E. Kolomeitsev🇷🇺 · D. N. Voskresensky🇷🇺
Analyses for the NICER data indicate that there is no significant variation of the compact star radii within the mass range of 1.4 to 2.0 solar masses. Yamamoto et al. [Phys. Rev. C 108, 035811 (2023)] concluded recently that ``this feature cannot be reproduced by the hadronic matter due to the softening of the equation of state (EoS) by hyperon mixing, suggesting the possible existence of quark phases in neutron-star interiors.'' Using a collection of 162 purely nucleonic, hyperonic, and quarkish EoSs from CompOSE database and some other works, we verify that hyperons indeed lead to a significant difference in radii of stars of 1.4 and 2.0 solar masses, which diminishes in the presence of quarks. We compare the shapes of the mass-radius curves and show that hyperons and quarks in the neutron star cores prefer a particular curve shape with backbending. It is argued that the shape {is controlled by the density dependence} of the nuclear symmetry energy. We draw attention to the existence of a class of purely hadronic relativistic mean-field EoSs with scalar-field dependent hadron masses and coupling constants that satisfy the known constraints on the EoSs including the analyses of the new NICER data and the above requirement of no significant variation of the neutron star radii.
Comments:
9 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2404.09875 [pdf]
PRC(2024)·7 citations
09
[Submitted on 15 Apr 2024]
Charmonium Transport in Ultra-Relativistic Heavy-Ion Collisions at the LHC
Biaogang Wu🇺🇸 · Ralf Rapp🇺🇸
We provide an update on our semi-classical transport approach for quarkonium production in high-energy heavy-ion collisions, focusing on $J / ψ$ and $ψ (2 S)$ mesons in 5.02 TeV Pb-Pb collisions at the Large Hadron Collider (LHC) at both forward and mid-rapidity. In particular, we employ the most recent charm-production cross sections reported in pp collisions, which are pivotal for the magnitude of the regeneration contribution, and their modifications due to cold-nuclear-matter (CNM) effects. Multi-differential observables are calculated in terms of nuclear modification factors as a function of centrality, transverse momentum, and rapidity, including the contributions from bottom-decay feeddown. For our predictions for $ψ (2 S)$ production, the mechanism of sequential regeneration relative to the more strongly bound $J / ψ$ meson plays an important role in interpreting recent ALICE data.
Comments:
20 pages, 19 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2404.09881 [pdf]
Universe(2024)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE