Nuclear Theory·nucl-th

Wednesday·September 6, 2023

26 papers—14 primary·12 cross-listed

01
[Submitted on 1 Sept 2023]
Entropies, level-density parameters, and fission probabilities along the triaxially- and axially-symmetric fission paths in $^{296}$ Lv
A. Rahmatinejad · T. M. Shneidman · G. G. Adamian · N. V. Antonenko · P. Jachimowicz · M. Kowal
We employ a statistical approach to investigate the influence of axial asymmetry on the nuclear level density and entropy along the fission pathways of a superheavy nucleus, explicitly focusing on the $^{296}$ Lv isotope. These pathways are determined within multidimensional deformation spaces. Our analysis reveals a significant impact of triaxiality on entropy. Additionally, suppressing shell effects can alter the fission scenario depending on the available excitation energy. We derive the deformation-dependent level density parameter, which plays a crucial role in estimating the survival probability of a superheavy nucleus. Furthermore, we utilize a set of master equations to obtain the time-dependent fission probabilities and calculate the ratio of decay probabilities for both axial and triaxial paths.
Comments:
submitted to PRC
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2309.00701 [pdf]
EPJA(2024)·6 citations
02
[Submitted on 2 Sept 2023]
Predication of novel effects in rotational nuclei at high speed
Jian-You Guo
The study of high-speed rotating matter is a crucial research topic in physics due to the emergence of novel phenomena. In this paper, we combined cranking covariant density functional theory (CDFT) with a similar renormalization group approach to decompose the Hamiltonian from the cranking CDFT into different Hermit components, including the non-relativistic term, the dynamical term, the spin-orbit coupling, and the Darwin term. Especially, we obtained the rotational term, the term relating to Zeeman effect-like, and the spin-rotation coupling due to consideration of rotation and spatial component of vector potential. By exploring these operators, we aim to identify novel phenomena that may occur in rotating nuclei. Signature splitting, Zeeman effect-like, spin-rotation coupling, and spin current are among the potential novelties that may arise in rotating nuclei. Additionally, we investigated the observability of these phenomena and their dependence on various factors such as nuclear deformation, rotational angular velocity, and strength of magnetic field.
Comments:
7pages, 5figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex); Quantum Physics (quant-ph)
arXiv:
2309.00786 [pdf]
PLB(2024)·2 citations
03
[Submitted on 3 Sept 2023]
Resolving the $R_{pA}$ and $v_{2}$ puzzle of $D^{0}$ mesons in $p -$ Pb collisions
Chao Zhang🇨🇳 · Zi-Wei Lin🇺🇸 · Liang Zheng🇨🇳 · Shusu Shi🇨🇳
It has been difficult to reconcile the experimental data on the $D^{0}$ meson nuclear modification factor and elliptic flow in $p -$ Pb collisions at LHC energies. Here we study these observables with the string melting version of a multi-phase transport model, which has been improved with the implementation of the Cronin effect (or transverse momentum broadening) and independent fragmentation for charm quarks. Using a strong Cronin effect allows us to provide the first simultaneous description of the $D^{0}$ meson $R_{pA}$ and $v_{2}$ data at $p_{T} \leq$ 8 GeV $/ c$ . The model also provides a reasonable description of the $D^{0}$ meson $p_{T}$ spectra and the low- $p_{T}$ (below $\sim$ 2 GeV $/ c$ ) charged hadron spectra in $p + p$ and $p -$ Pb collisions as well as $R_{pA}$ and $v_{2}$ in $p -$ Pb collisions. We find that both parton scatterings and the Cronin effect are important for the $D^{0}$ meson $R_{pA}$ , while parton scatterings are mostly responsible for the $D^{0}$ meson $v_{2}$ . Our results indicate that it is crucial to include the Cronin effect for the simultaneous description of the $D^{0}$ meson $R_{pA}$ and $v_{2}$ . Since the Cronin effect is expected to grow with the system size, this work implies that the Cronin effect could also be important for heavy hadrons in large systems.
Comments:
6 pages, 3 figures, proceedings for the 11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2309.01215 [pdf]
PoS(2024)·4 citations
04
[Submitted on 4 Sept 2023]
$ΛΛ$ Interaction in a Nuclear Density Functional Theory and Hyperon Puzzle of the Neutron Star
Soonchul Choi🇰🇷 · Emiko Hiyama🇯🇵 · Chang Ho Hyun🇰🇷 · Myung-Ki Cheoun🇰🇷
A Skyrme-type effective potential is determined to describe the interaction between $Λ$ hyperons in nuclear medium. Experimental data of the binding energies of the double- $Λ$ ( $ΛΛ$ ) nuclei with mass numbers $A = 10$ -- $13$ are used to fit the parameters of the $ΛΛ$ interaction. As a result of the fitting, we obtain eight different sets of the $ΛΛ$ interaction parameters, which reproduces the input data within 5\% deviation from the experimental data on average. The eight $ΛΛ$ interactions are plugged in the calculation of the heavier $ΛΛ$ nuclei and the neutron star equation of state to explore the issue of hyperon puzzle. We found that the $ΛΛ$ interaction, specifically, p-wave interaction makes the equation of state stiff enough that the maximum mass of the neutron star can be as large as, or above $2 M_{⊙}$ .
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2309.01348 [pdf]
3 citations
05
[Submitted on 4 Sept 2023]
Light clusters in the liquid proto-neutron star inner crust
H. Dinh Thi🇫🇷 · A. F. Fantina🇫🇷 · F. Gulminelli🇫🇷
Being born hot from core-collapse supernova, the crust of the proto-neutron star is expected to be made of a Coulomb liquid and composed of an ensemble of different nuclear species. In this work, we study the beta-equilibrated proto-neutron-star crust in the liquid phase in a self-consistent multi-component approach, employing a compressible liquid-drop description of the ions including the ion centre-of-mass motion. Particular care is also devoted to the calculation of the rearrangement term, thus ensuring thermodynamic consistency. We compare the results of the multi-component plasma calculations with those obtained within a one-component (single-nucleus) approach, showing that important differences arise between the predictions of the two treatments. In particular, the abundances of helium clusters become important using a complete multi-component plasma approach, and eventually dominate the whole distribution at higher temperature in the crust.
Comments:
Submitted to the European Physical Journal A (EPJA) for the Topical Collection "The Nuclear Many-Body Problem"
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2309.01533 [pdf]
EPJA(2023)·8 citations
06
[Submitted on 4 Sept 2023]
Ab initio calculation of the alpha-particle monopole transition form factor
Ulf-G. Meißner · Shihang Shen · Serdar Elhatisari · Dean Lee
We present a parameter-free ab initio calculation of the $α$ -particle monopole transition form factor in the framework of nuclear lattice effective field theory. We use a minimal nuclear interaction that was previously used to reproduce the ground state properties of light nuclei, medium-mass nuclei, and neutron matter simultaneously with no more than a few percent error in the energies and charge radii. The results for the monopole transition form factor are in good agreement with recent precision data from Mainz.
Comments:
5+3 pages, 3+4 figures, version accepted in Physical Review Letters, title shortened, more details in the supplemental material, references updated
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2309.01558 [pdf]
PRL(2024)·35 citations
07
[Submitted on 4 Sept 2023]
Chiral crossover vs chiral density wave in dense nuclear matter
Savvas Pitsinigkos🇬🇧 · Andreas Schmitt🇬🇧
We employ a model based on nucleonic and mesonic degrees of freedom to discuss the competition between isotropic and anisotropic phases in cold and dense matter. Assuming isotropy, the model exhibits a chiral phase transition which is of second order in the chiral limit and becomes a crossover in the case of a realistic pion mass. This observation crucially depends on the presence of the nucleonic vacuum contribution. Allowing for an anisotropic phase in the form of a chiral density wave can disrupt the smooth crossover. We identify the regions in the parameter space of the model where a chiral density wave is energetically preferred. A high-density re-appearance of the chiral density wave with unphysical behavior, as seen in previous studies, is avoided by a suitable renormalization scheme. A nonzero pion mass tends to disfavor the anisotropic phase compared to the chiral limit and we find that, within our model, the chiral density wave is only realized for baryon densities of at least about 6 times nuclear saturation density.
Comments:
22 pages, 6 figures; v2: minor clarifications, references added, version to appear in PRD; v3: typos in eqs. (17) and (34a) corrected (with no consequences for the rest of the paper)
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2309.01603 [pdf]
PRD(2024)·9 citations
08
[Submitted on 4 Sept 2023]
Evolution of Efimov States
Sebastian M. Dawid🇺🇸 · Md Habib E Islam🇺🇸 · Raúl A. Briceño🇺🇸 · Andrew W. Jackura🇺🇸
The Efimov phenomenon manifests itself as an emergent discrete scaling symmetry in the quantum three-body problem. In the unitarity limit, it leads to an infinite tower of three-body bound states with energies forming a geometric sequence. In this work, we study the evolution of these so-called Efimov states using relativistic scattering theory. We identify them as poles of the three-particle $S$ matrix and trace their trajectories in the complex energy plane as they evolve from virtual states through bound states to resonances. We dial the scattering parameters toward the unitarity limit and observe the emergence of the universal scaling of energies and couplings -- a behavior known from the non-relativistic case. Interestingly, we find that Efimov resonances follow unusual, cyclic trajectories accumulating at the three-body threshold and then disappear at some values of the two-body scattering length. We propose a partial resolution to this "missing states" problem.
Comments:
15 pages, 10 figures,
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Atomic Physics (physics.atom-ph)
arXiv:
2309.01732 [pdf]
PRA(2024)·29 citations
09
[Submitted on 4 Sept 2023]
Thermodynamics of an updated hadronic resonance list and influence on hadronic transport
Jordi Salinas San Martín🇺🇸 · Renan Hirayama🇩🇪 · Jan Hammelmann🇩🇪 · Jamie M. Karthein🇺🇸 · Paolo Parotto🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Claudia Ratti🇺🇸 · Hannah Elfner🇩🇪
Hadron lists based on experimental studies summarized by the Particle Data Group (PDG) are a crucial input for the equation of state and thermal models used in the study of strongly-interacting matter produced in heavy-ion collisions. Modeling of these strongly-interacting systems is carried out via hydrodynamical simulations, which are followed by hadronic transport codes that also require a hadronic list as input. To remain consistent throughout the different stages of modeling of a heavy-ion collision, the same hadron list with its corresponding decays must be used at each step. It has been shown that even the most uncertain states listed in the PDG from 2016 are required to reproduce partial pressures and susceptibilities from Lattice Quantum Chromodynamics with the hadronic list known as the PDG2016+. Here, we update the hadronic list for use in heavy-ion collision modeling by including the latest experimental information for all states listed in the Particle Data Booklet in 2021. We then compare our new list, called PDG2021+, to Lattice Quantum Chromodynamics results and find that it achieves even better agreement with the first principles calculations than the PDG2016+ list. Furthermore, we develop a novel scheme based on intermediate decay channels that allows for only binary decays, such that PDG2021+ will be compatible with the hadronic transport framework SMASH. Finally, we use these results to make comparisons to experimental data and discuss the impact on particle yields and spectra.
Comments:
17 pages, 16 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2309.01737 [pdf]
27 citations
10
[Submitted on 4 Sept 2023]
Far-from-equilibrium bulk-viscous transport coefficients in neutron star mergers
Yumu Yang · Mauricio Hippert · Enrico Speranza · Jorge Noronha
We investigate the weak-interaction-driven bulk-viscous transport properties of $n p e$ matter in the neutrino transparent regime. Previous works assumed that the induced bulk viscosity correction to pressure, near beta equilibrium, is linear in deviations from the equilibrium charge fraction. We show that this is not always true for (some) realistic equations of state at densities between one and three times saturation density. This nonlinear nature of the perturbation around equilibrium motivates a far-from-beta-equilibrium description of bulk-viscous transport in neutron star mergers, which can be precisely achieved using a new Israel-Stewart formulation with resummed bulk and relaxation time transport coefficients. The computation of these transport coefficients depends on out-of-beta-equilibrium pressure corrections, which can be computed for a given equation of state. We calculate these coefficients for equations of state that satisfy the latest constraints from multi-messenger observations from LIGO/VIRGO and NICER. We show that varying the nuclear symmetry energy $J$ and its slope $L$ can significantly affect the transport coefficients and the nonlinear behavior of the out-of-equilibrium pressure corrections. Therefore, having better constraints on $J$ and $L$ will directly impact our understanding of bulk-viscous processes in neutron star mergers.
Comments:
31 pages, 17 figures, 5 appendices, matches version accepted for publication in Physical Review C
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2309.01864 [pdf]
PRC(2024)·39 citations
11
[Submitted on 5 Sept 2023]
Clustering effects in the $^{6}$ Li(p, $^{3}$ He) $^{4}$ He reaction at astrophysical energies
Salvatore Simone Perrotta · Maria Colonna · José Antonio Lay
Background: The understanding of nuclear reactions between light nuclei at energies below the Coulomb barrier is important for several astrophysical processes, but their study poses experimental and theoretical challenges. At sufficiently low energies, the electrons surrounding the interacting ions affect the scattering process. Moreover, the clustered structure of some of these nuclei may play a relevant role on the reaction observables. Purpose: In this article, we focus on a theoretical investigation of the role of clustered configurations of $^{6}$ Li in reactions of astrophysical interest. Methods: The $^{6}$ Li(p, $^{3}$ He) $^{4}$ He reaction cross section is described considering both the direct transfer of a deuteron as a single point-like particle in Distorted Wave Born Approximation (DWBA), and the transfer of a neutron and a proton in second-order DWBA. A number of two- and three-cluster structure models for $^{6}$ Li are compared. Results: Within the two-cluster structure model, we explore the impact of the deformed components in the $^{6}$ Li wave-function on the reaction of interest. Within the three-cluster structure model, we gauge the degree of $α$ -d clustering and explicitly probe its role on specific features of the reaction cross section. We compare the energy trend of the astrophysical $S$ factor deduced in each case. Conclusions: Clustered $^{6}$ Li configurations lead in general to a significant enhancement of the astrophysical factor in the energy region under study. This effect only originates from clustering, whereas static deformations of the ground-state configuration play a negligible role at very low energies.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2309.01929 [pdf]
0 citations
12
[Submitted on 5 Sept 2023]
Microscopic investigation of one- and two-proton decay from the excited states of 10C
Qing Zhao · Masaaki Kimura · Bo Zhou · Seung-heon Shin
We present microscopic cluster model calculations for the 1p and 2p decays of the 0+2 and 2+2 states of 10C. With the R-matrix method, we have estimated the decay widths. The obtained 1p and 2p decay widths are in good agreement with the recent experimental data and support the validity of the di-proton approximation for the 2p decay of 10C(0+2). We also show the suppression of the 1p decay of the 10C(0+2) state due to the structure mismatch with the decay channel.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2309.02100 [pdf]
PLB(2024)·5 citations
13
[Submitted on 5 Sept 2023]
The role of three-nucleon potentials within the shell model: past and present
L. Coraggio · G. De Gregorio · T. Fukui · A. Gargano · Y. Z. Ma · Z. H. Cheng · F. R. Xu
We survey the impact of nuclear three-body forces on structure properties of nuclei within the shell model. It has long been acknowledged, since the seminal works of Zuker and coworkers, that three-body forces play a fundamental role in making the monopole component of shell-model Hamiltonians, derived from realistic nucleon-nucleon potentials, able to reproduce the observed evolution of the shell structure. In the vast majority of calculations, however, their effects have been taken into account by shell-model practitioners by introducing ad hoc modifications of the monopole matrix elements. During last twenty years, a new theoretical approach, framed within the chiral perturbation theory, has progressed in developing nuclear potentials, where two- and many-body components are naturally and consistently built in. This new class of nuclear forces allows to carry out nuclear structure studies that are improving our ability to understand nuclear phenomena in a microscopic approach. We provide in this work an update on the status of the nuclear shell model based on realistic Hamiltonians that are derived from two- and three-nucleon chiral potentials, focusing on the role of the three-body component to provide the observed shell evolution and closure properties, as well as the location of driplines. To this end, we present the results of shell-model calculations and their comparison with recent experimental measurements, which enlighten the relevance of the inclusion of three-nucleon forces to master our knowledge of the physics of atomic nuclei.
Comments:
Accepted for publication in Progress in Particle and Nuclear Physics
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2309.02314 [pdf]
PPNP(2024)·18 citations
14
[Submitted on 5 Sept 2023]
Neural Network Solutions of Bosonic Quantum Systems in One Dimension
Paulo F. Bedaque · Hersh Kumar · Andy Sheng
Neural networks have been proposed as efficient numerical wavefunction ansatze which can be used to variationally search a wide range of functional forms for ground state solutions. These neural network methods are also advantageous in that more variational parameters and system degrees of freedom can be easily added. We benchmark the methodology by using neural networks to study several different integrable bosonic quantum systems in one dimension and compare our results to the exact solutions. While testing the scalability of the procedure to systems with many particles, we also introduce using symmetric function inputs to the neural network to enforce exchange symmetries of indistinguishable particles.
Comments:
12 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th); cond-mat.dis-nn (cond-mat.dis-nn); Quantum Gases (cond-mat.quant-gas); Quantum Physics (quant-ph)
arXiv:
2309.02352 [pdf]
PRC(2024)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE