Nuclear Theory·nucl-th

Wednesday·July 12, 2023

11 papers—5 primary·6 cross-listed

01
Determination of matter radius and neutron-skin thickness of $^{60, 62, 64}$ Ni from reaction cross section of proton scattering on $^{60, 62, 64}$ Ni targets (published in Results in Physics)
Shingo Tagami · Tomotsugu Wakasa · Masanobu Yahiro
In our previous work, we determined matter radii $r_{m} (exp)$ and neutron-skin thickness $r_{skin} (exp)$ from reaction cross sections $σ_{R} (exp)$ of proton scattering on $^{208}$ Pb, $^{58}$ Ni, $^{40, 48}$ Ca, $^{12}$ C targets, using the chiral (Kyushu) $g$ -matrix folding model with the densities calculated with Gogny-D1S-HFB (D1S-GHFB) with angular momentum projection (AMP). The resultant $r_{skin} (exp)$ agree with the PREX2 and CREX values. As for $^{58}$ Ni, our value is consistent with one determined from the differential cross section for $^{58}$ Ni+ $^{4}$ He scattering. As for p+ $^{60, 62, 64}$ N scattering, $σ_{R} (exp)$ are available as a function of incident energies $E_{in}$ , where $E_{in} = 22.8 \sim 65.5$ ~MeV for $^{60}$ Ni, $E_{in} = 40, 60.8$ ~MeV for $^{62}$ Ni, $E_{in} = 40, 60.8$ ~MeV for $^{64}$ Ni. Our aim is to determine matter radii $r_{m} (exp)$ for $^{60, 62, 64}$ Ni from the $σ_{R} (exp)$ . Our method is the Kyushu $g$ -matrix folding model with the densities scaled from D1S-GHFB+AMP densities, Our skin values are $r_{skin} (exp) = 0.076 \pm 0.019, 0.106 \pm 0.192, 0.162 \pm 0.176$ ~fm, and $r_{m} (exp) = 3.759 \pm 0.011, 3.811 \pm 0.107, 3.864 \pm 0.101$ ~fm for $^{60, 62, 64}$ Ni, respectively.
nucl-thnucl-ex2 citations
02
Effects of neutron-rich nuclei masses on symmetry energy
Seonghyun Kim · Dukjae Jang · Soonchul Choi · Tsuyoshi Miyatsu · Myung-Ki Cheoun
We explore the impact of neutron-rich nuclei masses on the symmetry energy properties using the mass table evaluated by the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) model. First, using the semi-empirical mass formula with the DRHBc mass table, we investigate the symmetry energy at saturation density $ρ_{0}$ , denoted as $S_{0}$ , and the ratio of surface to volume contributions to the symmetry energy, $κ$ . As a result, we obtain $S_{0} = 27.85 MeV$ ( $κ = 1.38$ ) for $a_{sym} (A) = S_{0} (1 - κ A^{- 1/3})$ (Type I) and $S_{0} = 32.66 MeV$ ( $κ = 3.15$ ) for $a_{sym} (A) = S_{0} (1 + κ A^{- 1/3})^{- 1}$ (Type II), which are lower than those obtained using the AME2020 mass table, $S_{0} = 28.54 MeV$ ( $κ = 1.29$ ) for Type I and $S_{0} = 33.81 MeV$ ( $κ = 3.04$ ) for Type II. Second, we further investigate the effect of these changes in $a_{sym} (A)$ on the density-dependent symmetry energy by employing the empirical model of $S (ρ) = C_{k} (ρ / ρ_{0})^{2/3} + C_{1} (ρ / ρ_{0}) + C_{2} (ρ / ρ_{0})^{γ}$ and universal relation of $a_{sym} (A = 208) = S (ρ = 0.1 fm^{- 3})$ . Compared to the experimental constraints, we find that $S_{0}$ and slope parameter $L$ , determined by the DRHBc mass table with Type II, are more suitable to explain the constraints by heavy ion collisions and isobaric analog states than AME2020. We also discuss the neutron skin thickness derived from the $L$ , comparing it with experimental measurements.
nucl-th0 citations
03
Neutron star equation of state: identifying hadronic matter characteristics
Constança Providência🇵🇹 · Tuhin Malik🇵🇹 · Milena Bastos Albino🇵🇹 · Márcio Ferreira🇵🇹
The general behavior of the nuclear equation of state (EOS), relevant for the description of neutron stars (NS), is studied within a relativistic mean field description of nuclear matter. Different formulations, both with density dependent couplings and with non-linear mesonic terms, are considered and their predictions compared and discussed. A special attention is drawn to the effect on the neutron star properties of the inclusion of exotic degrees of freedom as hyperons. Properties such as the speed of sound, the trace anomaly, the proton fraction and the onset of direct Urca processes inside neutron stars are discussed. The knowledge of the general behavior of the hadronic equation of state and the implication it has on the neutron star properties will allow to identify signatures of a deconfinement phase transition discussed in other studies.
nucl-thastro-ph.HEhep-phChapter "Relativistic Description of the …·25 citations
04
Interplay of effects of neutron skins in coordinate space and proton skins in momentum space on hard photons emission in heavy-ion collisions around Fermi Energy
Wen-Mei Guo · Bao-An Li · Gao-Chan Yong
Within an isospin- and momentum-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model, we investigate the hard photons emission from neutron-proton bremsstrahlung in reaction system of $^{208} P b +^{208} P b$ around Fermi energy. Effects of neutron skins in coordinate ( $r$ ) space and proton skins in momentum ( $k$ ) space on the time evolution, the angular distribution, and the transverse momentum spectra of hard photons with different energies are studied. It is shown that the emission of direct hard photons is sensitive to the neutron skin, which has larger effects for more energetic hard photons. Meanwhile, we find that the proton skins have an important influence on the emission of direct hard photons, and its effect is actually even larger than that of neutron skins. It needs to take the effect of proton skins into account when we determine the size of neutron skins by comparing transport mode predictions of hard photons with the corresponding experiment measurements.
nucl-thPRC(2023)·8 citations
05
Quantum entanglement patterns in the structure of atomic nuclei within the nuclear shell model
A. Pérez-Obiol🇪🇸 · S. Masot-Llima🇪🇸 · A.M. Romero🇪🇸 · J. Menéndez🇪🇸 · A. Rios🇪🇸 · A. García-Sáez🇪🇸 · B. Juliá-Díaz🇪🇸
Quantum entanglement offers a unique perspective into the underlying structure of strongly-correlated systems such as atomic nuclei. In this paper, we use quantum information tools to analyze the structure of light and medium-mass berillyum, oxygen, neon and calcium isotopes within the nuclear shell model. We use different entanglement metrics, including single-orbital entanglement, mutual information, and von Neumann entropies for different equipartitions of the shell-model valence space and identify mode-entanglement patterns related to the energy, angular momentum and isospin of the nuclear single-particle orbitals. We observe that the single-orbital entanglement is directly related to the number of valence nucleons and the energy structure of the shell, while the mutual information highlights signatures of proton-proton and neutron-neutron pairing, as well as nuclear deformation. Proton and neutron orbitals are weakly entangled by all measures, and in fact have the lowest von Neumann entropies among all possible equipartitions of the valence space. In contrast, orbitals with opposite angular momentum projection have relatively large entropies, especially in spherical nuclei. This analysis provides a guide for designing more efficient quantum algorithms for the noisy intermediate-scale quantum era.
nucl-thquant-phEPJA(2023)·47 citations

Affiliations

first authorsco-authorsvia INSPIRE

Determination of matter radius and neutron-skin thickness of 60,62,64Ni from reaction cross section of proton scattering on 60,62,64Ni targets (published in Results in Physics)

Effects of neutron-rich nuclei masses on symmetry energy

Neutron star equation of state: identifying hadronic matter characteristics

Interplay of effects of neutron skins in coordinate space and proton skins in momentum space on hard photons emission in heavy-ion collisions around Fermi Energy

Quantum entanglement patterns in the structure of atomic nuclei within the nuclear shell model

Affiliations

Determination of matter radius and neutron-skin thickness of $^{60, 62, 64}$ Ni from reaction cross section of proton scattering on $^{60, 62, 64}$ Ni targets (published in Results in Physics)