Nuclear Theory·nucl-th

Tuesday·October 1, 2024

24 papers—12 primary·12 cross-listed

01
[Submitted on 27 Sept 2024]
Probing Nuclear Structure of Heavy Ions at the Large Hadron Collider
Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸
We perform high-statistics simulations to study the impacts of nuclear structure on the ratios of anisotropic flow observables in $^{208}$ Pb+ $^{208}$ Pb and $^{129}$ Xe+ $^{129}$ Xe collisions at the Large Hadron Collider. Even with $40%$ difference in atomic numbers between $^{208}$ Pb and $^{129}$ Xe nuclei, the ratios of anisotropic flow in the same centrality class between the two collision systems are strongly affected by the nuclear structure inputs in the initial state. The ratios of $v_{2} {4} / v_{2} {2}$ in these collisions are sensitive to the nuclear skin thickness of the colliding nuclei, providing indirect constraints on the nuclei's neutron skin. Our model predictions serve as a benchmark to compare with experimental measurements.
Comments:
8 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2409.19064 [pdf]
PRC(2024)·27 citations
02
[Submitted on 28 Sept 2024]
Exploring the Diversity of Nuclear Density through Information Entropy
Wei-Hu Ma · Yu-Gang Ma
This study explores the role of information entropy in understanding nuclear density distributions, including both stable configurations and non-traditional structures such as neutron halos and $α$ -clustering. By quantifying the uncertainty and disorder inherent in nucleon distributions in nuclear many-body systems, information entropy provides a macroscopic measure of the physical properties of the system. A more dispersed and disordered density distribution results in a higher value of information entropy. This intrinsic relationship between information entropy and system complexity allows us to quantify uncertainty and disorder in nuclear structures by analyzing various geometric parameters such as nuclear radius, diffuseness, neutron skin, and cluster structural features.
Comments:
10 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2409.19260 [pdf]
Entropy(2024)·3 citations
03
[Submitted on 28 Sept 2024]
Nucleation of baryons in relativistic hadron-nucleus collisions
A. Ergun🇹🇷 · N. Buyukcizmeci🇹🇷 · A. Kittiratpattana🇩🇪 · T. Reichert🇩🇪 · A. S. Botvina🇩🇪 · M. Bleicher🇩🇪
We suggest a new theoretical method to describe the baryon clusterization of nuclei in hadron-nucleus reactions. As an example we have explored the nuclei production in $π^{-} + C$ and $π^{-} + W$ collisions at p $_{l ab}$ =1.7 GeV by using the hybrid approach consisting of the Ultra Relativistic Quantum Dynamics Model (UrQMD) and the Statistical Multifragmentation Model (SMM). The UrQMD describes the production of new baryons, and the propagation toward the subnuclear densities with the fluctuations leading to the formation of excited baryonic clusters. The SMM describes the production of final nuclei and hypernuclei after interaction of baryons inside these clusters. We demonstrate the transverse momenta, rapidity, mass distributions and excitation energies of both primary clusters and final nuclei (including hypernuclei). The results of the UrQMD and UrQMD+SMM model calculations for different clusterization parameters are compared with the available HADES experimental data on baryon production, providing a very promising window for future research on nuclei and hypernuclei formation in these reactions.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2409.19290 [pdf]
NPA(2025)·1 citation
04
[Submitted on 28 Sept 2024]
Chebyshev Based Spectral Representations of Neutron-Star Equations of State
Lee Lindblom · Tianji Zhou
Causal parametric representations of neutron-star equations of state are constructed here using Chebyshev polynomial based spectral expansions. The accuracies of these representations are evaluated for a collection of model equations of state from a variety of nuclear-theory models and also a collection of equations of state with first- or second-order phase transitions of various sizes. These tests show that the Chebyshev based representations are convergent (even for equations of state with phase transitions) as the number of spectral basis functions is increased. This study finds that the Chebyshev based representations are generally more accurate than a previously studied power-law based spectral representation, and that pressure-based representations are generally more accurate than those based on enthalpy.
Comments:
7 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
arXiv:
2409.19421 [pdf]
PRD(2024)·6 citations
05
[Submitted on 28 Sept 2024]
Investigating the weak charge of $^{48}$ Ca using a dispersive optical model
N. L. Calleya · M. C. Atkinson · W. H. Dickhoff
A new nonlocal dispersive-optical-model analysis has been carried out for neutrons and protons in $^{48}$ Ca that reproduces the weak-form-factor measurement of CREX. In addition to elastic-scattering angular distributions, total and reaction cross sections, single-particle energies, the neutron and proton numbers, and the charge distribution, the CREX-measured weak form factor has been fit to extract the neutron and proton self-energies both above and below the Fermi energy. The resulting single-particle propagators yield a weak form factor of $F_{W} = 0.125 \pm 0.05$ and a neutron skin of $R_{skin} = 0.152 \pm 0.05$ fm, in good agreement with CREX. The rearrangement of the neutron distribution to accommodate such a thin neutron skin results in the high-momentum content of the neutrons exceeding that of the protons, in contrast to what is expected from high-energy two-nucleon knockout measurements by the CLAS collaboration and ab initio asymmetric matter calculations. The present analysis also emphasizes the importance of neutron experimental data in constraining weak charge observables necessary for a precise description of neutron densities. Notably, the neutron reaction cross section and further parity-violating experiments weak form factor measurements are essential to generate a unique way to determine the $^{48}$ Ca neutron distribution in this framework.
Comments:
Revised (e,e'p) figure
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2409.19438 [pdf]
PLB(2025)·3 citations
06
[Submitted on 28 Sept 2024]
State-of-the-art of Strangeness in Quark Matter Theory 2024
Jacquelyn Noronha-Hostler🇺🇸
I discuss the theoretical developments in related to Strangeness in Quark Matter (SQM) leading up to the SQM2024 conference. These advances include mapping out the Quantum Chromodynamics phase diagram; puzzles that exist in hadron physics from light to heavy particles; and advanced in relativistic hydrodynamics with the inclusion of spin and magnetic fields.
Comments:
6 pages, Prepared for the proceedings of the 21st International Conference on Strangeness in Quark Matter (SQM 2024), 2-7/6/2023, Université de Strasbourg, France
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2409.19486 [pdf]
0 citations
07
[Submitted on 29 Sept 2024]
Femtoscopic study of the $Ω α$ interaction in heavy-ion collisions
Faisal Etminan🇮🇷
The two-particle momentum correlation between the Omega-baryon ( $Ω$ ) and the $^{4} H e (α)$ in high-energy heavy ion collisions is explored. Such correlations as an alternative source of information can help us further understand the interaction between $Ω$ and nucleons (N). $Ω α$ potentials in the single-folding potential approach are constructed by employing two different available $Ω N$ interactions in $^{5} S_{2}$ channel, i.e, one is based on the (2 + 1)-flavor lattice QCD simulations near the physical point by the HAL QCD collaboration, and another is based on the meson exchanges with effective Lagrangian, where in the latter case coupled channels effect is considered. It is found that the correlation functions at small size source depends on the used potential model. This implicitly means that at high density nuclear medium, $Ω α$ momentum correlation could drive the feature of $Ω N$ interactions. Moreover, by extracting the scattering length and the effective range from obtained $Ω α$ potentials, the correlation functions are calculated within the Lednicky-Lyuboshits (LL) formalism. It is shown that since the $Ω α$ has large interaction range, the LL formula leads to different results at small source size.
Comments:
14 pages, 9 Figures, 1 Table. arXiv admin note: text overlap with arXiv:2406.03572
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2409.19705 [pdf]
PRC(2025)·8 citations
08
[Submitted on 29 Sept 2024]
On elliptic flow and the blast-wave model
Boris Tomasik🇨🇿
Extensions of the blast-wave model for the description of non-central collisions are reviewed and the physics behind them is explained and illustrated. It is shown how the second-order anisotropy in expansion velocity together with the anisotropy in the shape or the density profile of the fireball determine the elliptic flow of the produced hadrons. Ambiguities and limitations of the models are discussed and different models are compared among themselves and with example data. It is concluded that model results should always be compared to $v_{2} (p_{t})$ from several identified species in order to receive meaningful results about the freeze-out stage of the fireball and that even such a comparison may not be conclusive as the models may not be able to reproduce all relevant data.
Comments:
18 pages, 8 figures, minireview written for special volume of selected papers from the Zimanyi School 2023. New appendix added in the revised version on low-pt behaviour of v2. More explanatios added on some places. Results unchanged. Accepted in Int. J. Mod. Phys. A
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2409.19758 [pdf]
Int.J.Mod.Phys.A(2025)·4 citations
09
[Submitted on 30 Sept 2024]
Anisotropic hydrodynamics with boost-non-invariant expansion
Shile Chen🇨🇳 · Shuzhe Shi🇨🇳
We establish the anisotropic hydrodynamics (aHydro) equations based on a boost-non-invariant longitudinally expanding system. Good consistency is found in the comparison between the aHydro results with those from the Boltzmann equation under relaxation time approximation. We also obtain corresponding attractor solution and observe the time delay of convergence when increasing the absolute value of the rapidity. We finally show that the rapidity dependence is solved by introducing the redefined attractor variables to compensate the time delay effect.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2409.19897 [pdf]
PRD(2025)·5 citations
10
[Submitted on 30 Sept 2024]
SMASH as an event generator for heavy-ion collisions
A. Sciarra🇩🇪 · H. Elfner🇩🇪
In this article we present an overview of the SMASH hadronic transport approach that is applied for non-equilibrium dynamics of hadrons in \heavyion\ collisions. We will give an overview about the ingredients of the approach and the applications for the dynamical description of \heavyion\ collisions and for calculations of fundamental properties of the hadron gas. The main emphasis of the article will be the infrastructure for sustainable software development that we have developed over the last 10 years including extensive unit tests and continuous integration. We will also provide one section about the performance of the code and how it can be analyzed and improved in the future.
Comments:
9 pages, 4 figures, invited contribution to Frontiers on 'Promoting Green Computing in High-Energy Physics and Astrophysics'
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2409.20024 [pdf]
Front.in Phys.(2024)·7 citations
11
[Submitted on 30 Sept 2024]
Nuclear shape / phase transitions in the N = 40, 60, 90 regions
Dimitrios Petrellis (1) · Adam Prášek (2) · Petr Alexa (2) · Dennis Bonatsos (3) · Gabriela Thiamová (4) · Petr Veselý (1) ((1) Nuclear Physics Institute of the Czech Academy of Sciences, (2) Department of Physics, VŠB - Technical University Ostrava, (3) Institute of Nuclear and Particle Physics, National Centre for Scientific Research "Demokritos", (4) Universite Grenoble 1, CNRS, LPSC, Institut Polytechnique de Grenoble, IN2P3)
We investigate the isotopes of Se, Zr, Mo and Nd in the regions with N = 40, 60 and 90, where a first-order shape / phase transition, from spherical to deformed, can be observed. The signs of phase transitional behavior become evident by examining structure indicators, such as certain energy ratios and B(E2) transition rates and, in particular, how they evolve with neutron number. Microscopic mean-field calculations using the Skyrme-Hartree-Fock + Bardeen-Cooper-Schrieffer framework also reveal structural changes when considering the evolution of the resulting potential energy curves as functions of deformation. Finally, macroscopic calculations, using the Algebraic Collective Model, specifically for $^{74}$ Se, $^{102}$ Mo and $^{150}$ Nd, after fitting its parameters to experimental spectra, result in potentials that resemble some of the potentials proposed in the framework of the Bohr Hamiltonian to describe shape transitions in nuclei.
Comments:
5 pages, 4 figures, 7th Workshop of the Hellenic Institute of Nuclear Physics (HINPw7)
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2409.20110 [pdf]
EPJ Web Conf.(2024)·0 citations
12
[Submitted on 30 Sept 2024]
Big Bang: a theory or fact
D. N. Basu
The discovery and confirmation that some nuclides were formed soon after the Big Bang is one of the strongest arguments in favour of the Hot Big Bang theory. The process of combining protons and neutrons in a hot, expanding universe is known as Big Bang nucleosynthesis (or, occasionally, primordial nucleosynthesis). The only experiment that is currently constructed to be concurrently sensitive to all four known fundamental forces - gravitational, electromagnetic, strong and weak forces - is big bang nucleosynthesis, which offers our earliest test of cosmology. Combined, our theoretical comprehension of Big Bang nucleosynthesis and the measurement of primordial abundances constitute one of the most robust foundations for the conventional cosmological model. This deliberation provides modern calculations of Big Bang nucleosynthesis, help readers gain an intuitive knowledge of the process and give an overview of the most recent state-of-the-art measurements. Our trust in the current basic picture of cosmology is reinforced by the overall amazing agreement between Big Bang nucleosynthesis and many cosmological probes.
Comments:
11 pages including 2 figures and 1 table
Subjects:
Nuclear Theory (nucl-th); physics.pop-ph (physics.pop-ph)
arXiv:
2409.20299 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE