scholarly journals Stability of $\alpha$-chain states against disintegrations

2019 ◽  
Vol 2019 (6) ◽  
Author(s):  
Akihiro Tohsaki ◽  
Naoyuki Itagaki
Keyword(s):  
Cluster State ◽  
Alpha Decay ◽  
Pauli Principle ◽  
Nucleon Nucleon ◽  
Alpha Chain ◽  
Saturation Properties ◽  
Nucleon Nucleon Interaction ◽  
Three Body ◽  
Alpha Cluster ◽  
Alpha Scattering

Abstract We focus on the raison d’être of the $\alpha$-chain states on the basis of the fully microscopic framework, where the Pauli principle among all the nucleons is fully taken into account. Our purpose is to find the limiting number of $\alpha$ clusters on which the linear $\alpha$-cluster state can stably exist. How many $\alpha$ clusters can stably make an $\alpha$-chain state? We examine the properties of equally separated $\alpha$ clusters on a straight line and compare its stability with that on a circle. We also confirm its stability in terms of binary and ternary disintegrations including $\alpha$-decay and fission modes. For the effective nucleon–nucleon interaction we employ the F1 force, which has finite-range three-body terms and guarantees overall saturation properties of nuclei. This interaction also gives a reasonable binding energy and size of the $\alpha$ particle, and the $\alpha$–$\alpha$ scattering phase shift. The result astonishes us because we can point out the possible existence of $\alpha$-chain states with vast numbers of $\alpha$ clusters.

A SKYRME PARAMETRIZATION BASED ON NUCLEAR MATTER BHF CALCULATIONS

2000 ◽  
Vol 15 (20) ◽  
pp. 1287-1299 ◽  
Author(s):  
M. RASHDAN
Keyword(s):  
Nuclear Matter ◽  
Density Functional ◽  
Nucleon Nucleon ◽  
Energy Density Functional ◽  
Hartree Fock ◽  
Saturation Properties ◽  
Nucleon Nucleon Interaction ◽  
Three Body ◽  
Finite Nuclei

Using a modified energy density functional of nuclear matter derived by solving the Bethe–Goldstone equation with a realistic nucleon–nucleon interaction and by including corrections due to relativistic and three-body effects, an effective Skyrme parameter set is derived. These corrections are found to be important in order to well describe the saturation properties of nuclear matter. The obtained Skyrme parameter set, which we denoted by SKRA, is found to better account for nuclear correlations and satisfactory describes finite nuclei, when used in the Skyrme–Hartree–Fock theory. The SKRA interaction can also be considered as an important step toward removing the ambiguities in the determination of Skyrme parameters.

scholarly journals Low-energy neutron scattering on light nuclei and $^{19}$B as a $^{17}$B-$n$-$n$ three-body system in the unitary limit

2020 ◽  
Author(s):  
Jaume Carbonell ◽  
Emiko Hiyama ◽  
Rimantas Lazauskas ◽  
Francisco Miguel Marqués
Keyword(s):  
Scattering Length ◽  
Nucleon Nucleon ◽  
Light Nuclei ◽  
Unitary Limit ◽  
Body System ◽  
Resonant States ◽  
Pauli Repulsion ◽  
Nucleus Scattering ◽  
Nucleon Nucleon Interaction ◽  
Three Body

We consider the evolution of the neutron-nucleus scattering length for the lightest nuclei. We show that, when increasing the number of neutrons in the target nucleus, the strong Pauli repulsion is weakened and the balance with the attractive nucleon-nucleon interaction results into a resonant virtual state in ^{18}18B. We describe ^{19}19B in terms of a ^{17}17B-nn-nn three-body system where the two-body subsystems ^{17}17B-nn and nn-nn are unbound (virtual) states close to the unitary limit. The energy of ^{19}19B ground state is well reproduced and two low-lying resonances are predicted. Their eventual link with the Efimov physics is discussed. This model can be extended to describe the recently discovered resonant states in ^{20,21}20,21B.

Clustering energy calculation in light alpha-conjugated nuclei

2020 ◽  
Vol 98 (10) ◽  
pp. 976-979
Author(s):  
Nafiseh Roshanbakht ◽  
Mohammadreza Shojaei
Keyword(s):  
Cluster State ◽  
Energy Levels ◽  
Nucleon Nucleon ◽  
Energy Calculation ◽  
Nucleon Interaction ◽  
Microscopic Method ◽  
Cluster Interaction ◽  
Spherical Structure ◽  
O Isotopes ◽  
Nucleon Nucleon Interaction

In this paper, clustering energy was investigated in light alpha-conjugate nuclei considering cluster–cluster interaction instead of nucleon–nucleon interaction and using the phenomenological non-microscopic method. The observed energy levels were calculated from the rotational band of 8Be, 12C, and 16O isotopes. The results showed that these isotopes, in their cluster state, have a non-spherical structure.

Systematic study of alpha-decay of super-heavy isotopes with Z = 120–126

2021 ◽  
pp. 2150033
Author(s):  
S. A. Seyyedi
Keyword(s):  
Spontaneous Fission ◽  
Alpha Decay ◽  
Nucleon Nucleon ◽  
Decay Modes ◽  
Nucleon Nucleon Interaction ◽  
Fragmentation Potential ◽  
Double Folding ◽  
Semi Empirical ◽  
Empirical Approaches ◽  
Good Agreement

Alpha-decay half-lives of the even–even superheavy isotopes with proton numbers [Formula: see text] have been calculated within the cluster model. The alpha-daughter potential was constructed by employing the density-dependent double-folding model with a realistic nucleon–nucleon interaction whose exchange part has a finite range approximation. The half-lives were calculated using Wentzel–Kramers–Brillouin (WKB) approximation with the alpha preformation factor. The results have shown that the computed alpha-decay half-lives were in good agreement with their counterpart calculated by different semi-empirical approaches. The obtained results have also shown a negative linear relationship between the logarithm of the preformation factor and the fragmentation potential for the understudy isotopes. Also, the calculated results have shown that isotopes [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] had longer half-lives than their adjacent isotopes, which indicates that the corresponding neutron or proton numbers have a magical or semi-magical properties. Furthermore, we have studied the competition between alpha-decay and spontaneous fission to predict possible decay modes from the even–even isotopes [Formula: see text]. The results revealed that the isotopes [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] had alpha-decay as a predominant mode of decay and the nuclei [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] could not survive from the spontaneous fission. We hope that the theoretical prediction could be helpful for future investigation in this field.

NUCLEON-NUCLEON CROSS SECTIONS IN ISOSPIN ASYMMETRIC NUCLEAR MATTER

2010 ◽  
Vol 19 (08n09) ◽  
pp. 1788-1793
Author(s):  
HONGFEI ZHANG ◽  
JIANMIN DONG ◽  
WEI ZUO ◽  
UMBERTO LOMBARDO
Keyword(s):  
Nuclear Matter ◽  
Cross Sections ◽  
Nucleon Nucleon ◽  
Density Region ◽  
Proton Proton ◽  
Asymmetric Nuclear Matter ◽  
Hartree Fock ◽  
Nucleon Nucleon Interaction ◽  
Three Body ◽  
Neutron Cross Sections

The in medium nucleon-nucleon (NN) cross sections in isospin asymmetric nuclear matter at various densities are investigated in the framework of Brueckner-Hartree-Fock theory with the Bonn B two-body nucleon-nucleon interaction supplemented with a new version microscopic three-body force (TBF). The TBF depresses the amplitude of cross sections at high density region. At low densities, the proton-proton and neutron-neutron cross sections decrease while the proton-neutron one increases as the asymmetry increases. But the sensitivity of the NN cross sections to the isospin asymmetry are reduced with the increasing density.

scholarly journals EFFECTIVE NUCLEON-NUCLEON INTERACTION AND FERMI LIQUID THEORY

2003 ◽  
Vol 17 (28) ◽  
pp. 5221-5225
Author(s):  
ACHIM SCHWENK ◽  
GERALD E. BROWN ◽  
BENGT FRIMAN
Keyword(s):  
Nuclear Matter ◽  
Fermi Liquid ◽  
Sum Rules ◽  
Pauli Principle ◽  
Nucleon Nucleon ◽  
Nucleon Interaction ◽  
Fermi Liquid Theory ◽  
Liquid Theory ◽  
Nucleon Nucleon Interaction ◽  
Group Flow

We present two novel relations between the quasiparticle interaction in nuclear matter and the unique low momentum nucleon-nucleon interaction in vacuum. These relations provide two independent constraints on the Fermi liquid parameters of nuclear matter. Moreover, the new constraints define two combinations of Fermi liquid parameters, which are invariant under the renormalisation group flow in the particle-hole channels. Using empirical values for the spin-independent Fermi liquid parameters, we are able to compute the major spin-dependent ones by imposing the new constraints as well as the Pauli principle sum rules.

scholarly journals A new scheme for heavy nuclei: proxy-SU(3)

2019 ◽  
Vol 25 ◽  
pp. 6
Author(s):  
D. Bonatsos ◽  
R. F. Casten ◽  
A. Martinou ◽  
I. E. Assimakis ◽  
N. Minkov ◽  
...  
Keyword(s):  
Short Range ◽  
Pauli Principle ◽  
Nucleon Nucleon ◽  
Orbit Interaction ◽  
Heavy Nuclei ◽  
Nucleon Interaction ◽  
Nucleon Nucleon Interaction ◽  
Nuclear Shell ◽  
Boson Approximation ◽  
Strong Spin

The SU(3) symmetry realized by J. P. Elliott in the sd nuclear shell is destroyed in heavier shells by the strong spin-orbit interaction. However, the SU(3) symmetry has been used for the description of heavy nuclei in terms of bosons in the framework of the Interacting Boson Approximation, as well as in terms of fermions using the pseudo-SU(3) approximation. We introduce a new fermionic approximation, called the proxy-SU(3), and we discuss how some of its novel predictions come out as a consequence of the short range of the nucleon-nucleon interaction and the Pauli principle.

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