The properties of neutron-star matter up to the appearance of hyperons are calculated with the aid of Skyrme potentials. The conditions for the appearance of Λ hyperons in matter and values of the ...density at the point of their appearance are analyzed for various parametrizations of nucleon-nucleon and hyperon-nucleon interactions. The dependence of the results on the magnitude of density-dependent forces, the degree of nonlocality, the behavior of the symmetry energy, and incompressibility of nuclear matter is examined.
The results obtained by measuring the angular and energy distributions of gamma rays originating from the inelastic scattering of 14.1-MeV neutrons by carbon and oxygen nuclei are presented. The ...measurements in question were performed by the tagged-neutron method in a beam of an ING-27 standard portable neutron generator. The angular distributions of gamma rays emitted by the 2
+
state of
12
С at 4.43 MeVand the 3
−
state of
16
O at 6.13 MeV were obtained.
.
New data on proton and neutron single-particle energies
E
n
l
j
of Si isotopes with neutron number
N
from 12 to 28 as well as occupation probabilities
N
n
l
j
of single-particle states of stable ...isotopes
28, 30
Si near the Fermi energy were obtained by the joint evaluation of the stripping and pick-up reaction data and excited state decay schemes of neighboring nuclei. The evaluated data indicate the following features of single-particle structure evolution: persistence of
Z
= 14 subshell closure with
N
increase, the new magicity of the number
N
= 16, and the conservation of the magic properties of the number
N
= 20 in Si isotopic chain. The features were described by the dispersive optical model. The calculation also predicts the weakening of
N
= 28 shell closure and demonstrates evolution of a bubble-like structure of the proton density distributions in neutron-rich Si isotopes.
At high densities that are achieved in neutron stars, there may be additional sensitivity to certain properties of the baryonic interaction. In the present work, we consider neutron stars consisting ...of nucleons, leptons, and Λ-hyperons with Skyrme baryonic force. We calculate different characteristics of neutron stars such as mass, radius and tidal deformability and investigate their dependence on the properties of the interactions.
An analysis of experimental data on the parameters of neutron and proton density distributions in atomic nuclei is performed. The diabatic potential for collisions between spherical nuclei with
Z
,
N
...≥ 8 is calculated using the resulting density parameters.
A study is performed of the spectra of neutron-rich
70–76
Ni isotopes in which the main configuration is determined by the filling of subshell 1
g
9/2
. Consideration is given to the dependence of ...the order of the ground state multiplet (GSM) levels and the splitting of seniority multiplet
from the position of state
In several isotopes, an especially low position of this state inverts levels with identical
but different seniority
Shift of the Proton Drip Line by Λ-Hyperons Kornilova, A. S.; Sidorov, S. V.; Lanskoy, D. E. ...
Physics of particles and nuclei letters,
10/2023, Letnik:
20, Številka:
5
Journal Article
Recenzirano
Addition of a Λ-hyperon to non-strange nuclei can lead to an increase in the binding energy and formation of a bound hypernucleus with an unbound nucleon core, effectively leading to the shift of the ...proton drip line on the hypernuclear chart. The structure of light proton-rich Λ-hypernuclei with 5 ≤
Z
≤ 12 is treated within the Hartree–Fock approach with effective potentials in the Skyrme form. We show that nuclei
8
C and
16
F are most likely can be bound by a hyperon.
For the stable silicon isotopes
28
Si and
30
Si, the energies and occupancies of single-particle states of the 1
d
2
s
shell are determined by analyzing the combined data for the nucleon stripping ...and pickup reactions. From the results of analysis and the available experimental data, the variation of the 1
d
2
s
proton-shell structure with increasing neutron number for the silicon isotopes with A = 26–34 is discussed.
In this paper, we propose a method of taking charge symmetry breaking (CSB) in hypernuclei and neutron stars into account within the framework of the Hartree–Fock approach with Skyrme interaction. ...The parameters of the contribution of
-Skyrme force leading to CSB are derived from the corresponding parameters of the hyperon-nucleon interaction in the meson exchange models. Based on the obtained parameters, the effect of charge symmetry breaking on the hyperon binding energy in carbon hypernuclei is analyzed. The effect of charge symmetry breaking on the characteristics of neutron stars, such as their maximum mass and radii, is considered for the first time.
Inelastic scattering of 14.1 MeV neutrons on iron Fedorov, N. A.; Grozdanov, D. N.; Kopatch, Yu. N. ...
The European physical journal. A, Hadrons and nuclei,
06/2021, Letnik:
57, Številka:
6
Journal Article
Recenzirano
An investigation of inelastic scattering of 14.1 MeV neutrons on an iron sample was carried out using an improved TANGRA (TAgged Neutron and Gamma RAys) setup at JINR (Dubna). The yields of the ...occurring
γ
-transitions and anisotropy of the emitted
γ
-rays were measured using the tagged neutron method. The setup with a high-purity germanium (HPGe) detector was used to obtain the energy spectrum of
γ
-rays. The setup with 18 BGO scintillation detectors positioned in a circle around the sample was used to obtain angular distributions of
γ
-rays. A detailed
γ
-spectrum for
(
n
,
X
γ
)
reactions was obtained and the
γ
-ray angular distribution was measured for the 847 keV and 1238 keV
γ
-transitions. The distribution was fitted by Legendre polynomials up to fourth order and the angular distribution coefficients
a
2
,
a
4
were extracted. A comparison with other published experimental results is given. Model calculations using computer code TALYS 1.9 were performed. The results of calculations are discussed in comparison with the obtained experimental data.
PDF
