scholarly journals Study of the Ground-State Energies of Some Nuclei Using Hybrid Model

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
R. Hussien ◽  
Sh. M. Sewailem ◽  
L. I. Abou-Salem
Keyword(s):  
Hybrid Model ◽  
Ground State ◽  
Nucleon Nucleon ◽  
Light Nuclei ◽  
Exchange Potential ◽  
Small Scale ◽  
Quark Interaction ◽  
Nucleon Nucleon Interaction ◽  
The One ◽  
Ground State Energies

The quark-quark (QQ) interaction as a perturbed term to the nucleon-nucleon interaction (NN) without any coupling between them is studied in a hybrid model. This model is used to calculate the ground-state energies of 2H1 and 4He2 nuclei. In a semirelativistic framework, this model is encouraged for light nuclei and the instanton-induced interaction by using the QQ potential and the NN interaction for a small scale around the hadron boundaries. This hybrid model depends on two theories, the one-boson exchange potential (OBEP) and the Cornell-dressed potential (CDP) for QQ. A small effect of quark-quark interaction is obtained on the values of the ground-state energies, around 6.7 and 1.2 percentage for 2H1 and 4He2, respectively nuclei.

scholarly journals The Ground-State Calculations for Some Nuclei by Mesonic Potential of Nucleon-Nucleon Interaction

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
K. M. Hanna ◽  
S. H. M. Sewailem ◽  
R. Hussien ◽  
L. I. Abou-Salem ◽  
Asmaa G. Shalaby
Keyword(s):  
Ground State ◽  
Degrees Of Freedom ◽  
Vector Fields ◽  
Theoretical Models ◽  
Nucleon Nucleon ◽  
Particle Energy ◽  
Exchange Potential ◽  
Hartree Fock ◽  
Scalar And Vector Fields ◽  
Nucleon Nucleon Interaction

The interaction of nucleon-nucleon (NN) has certain physical characteristics, indicated by nucleon, and meson degrees of freedom. The main purpose of this work is calculating the ground-state energies of  12H and  24He through the two-body system with the exchange of mesons (π, σ, and ω) that mediated between two nucleons. This paper investigates the NN interaction based on the quasirelativistic decoupled Dirac equation and self-consistent Hartree-Fock formulation. We construct a one-boson exchange potential (OBEP) model, where each nucleon is treated as a Dirac particle and acts as a source of pseudoscalar, scalar, and vector fields. The potential in the present work is analytically derived with two static functions of meson, the single-particle energy-dependent (SPED) and generalized Yukawa (GY) functions; the parameters used in meson functions are just published ones (mass, coupling constant, and cutoff parameters). The theoretical results are compared to other theoretical models and their corresponding experimental data; one can see that the SPED function gives more satisfied agreement than the GY function in the case of the considered nuclei.

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.

scholarly journals Wigner SU(4) symmetry, clustering, and the spectrum of $$^{12}$$C

2021 ◽  
Vol 57 (9) ◽  
Author(s):  
Shihang Shen ◽  
Timo A. Lähde ◽  
Dean Lee ◽  
Ulf-G. Meißner
Keyword(s):  
Excited States ◽  
Ground State ◽  
Nucleon Nucleon ◽  
Irreducible Representations ◽  
Spin Orbit ◽  
Hoyle State ◽  
Nucleon Interaction ◽  
Model Calculations ◽  
Nucleon Nucleon Interaction ◽  
Spin Orbit Interactions

AbstractWe present lattice calculations of the low-lying spectrum of $$^{12}$$ 12 C using a simple nucleon–nucleon interaction that is independent of spin and isospin and therefore invariant under Wigner’s SU(4) symmetry. We find strong signals for all excited states up to $$\sim 15$$ ∼ 15  MeV above the ground state, and explore the structure of each state using a large variety of $$\alpha $$ α cluster and harmonic oscillator trial states, projected onto given irreducible representations of the cubic group. We are able to verify earlier findings for the $$\alpha $$ α clustering in the Hoyle state and the second $$2^+$$ 2 + state of $$^{12}$$ 12 C. The success of these calculations to describe the full low-lying energy spectrum using spin-independent interactions suggest that either the spin-orbit interactions are somewhat weak in the $$^{12}$$ 12 C system, or the effects of $$\alpha $$ α clustering are diminishing their influence. This is in agreement with previous findings from ab initio shell model calculations.

AB INITIO NUCLEAR STRUCTURE CALCULATIONS OF p-SHELL NUCLEI WITH JISP16

2013 ◽  
Vol 22 (07) ◽  
pp. 1330016 ◽  
Author(s):  
PIETER MARIS ◽  
JAMES P. VARY
Keyword(s):  
Ab Initio ◽  
Magnetic Moments ◽  
Nucleon Nucleon ◽  
Quadrupole Moments ◽  
Nucleon Interaction ◽  
Excitation Energies ◽  
Nucleon Nucleon Interaction ◽  
Nuclear Structure Calculations ◽  
Structure Calculations ◽  
Ground State Energies

We review energies and magnetic moments of p-shell nuclei obtained with the ab initio No-Core Full Configuration (NCFC) approach using the JISP16 realistic nucleon–nucleon interaction. We present calculated ground state energies for all stable p-shell nuclei and selected unstable isotopes, as well as their magnetic moments. We also review excitation energies for narrow resonances of A = 6 to 9 nuclei. We compare our results with experimental data and with other ab initio calculations, where available. We illustrate how the decomposition of total angular momentum into intrinsic spin and orbital components provides insights into the structure of states and relationships among states. We illustrate the challenges of obtaining converged results for radii, quadrupole moments and B(E2) values.

Quark degrees of freedom and nuclear matter saturation

2019 ◽  
Vol 34 (39) ◽  
pp. 1950322
Author(s):  
Marcello Baldo ◽  
Zahra Asadi Aghbolaghi ◽  
Isaac Vidaña ◽  
Mohsen Bigdeli
Keyword(s):  
Nuclear Matter ◽  
Degrees Of Freedom ◽  
Nucleon Nucleon ◽  
Meson Exchange ◽  
Nucleon Interaction ◽  
S Wave ◽  
Nucleon Potential ◽  
Quark Interaction ◽  
Exchange Processes ◽  
Nucleon Nucleon Interaction

It has been found in previous works [M. Baldo and K. Fukukawa, Phys. Rev. Lett. 113, 241501 (2014); K. Fukukawa, M. Baldo, G. F. Burgio, L. Lo Monaco and H.-J. Schulze, Phys. Rev. 92, 065802 (2015)] that the nucleon–nucleon potential of [Y. Fujiwara, M. Kohno, C. Nakamoto and Y. Suzuki Phys. Rev. C 64, 054001 (2001); Y. Fujiwara et al., Phys. Rev. C 65, 014002 (2001)] gives an accurate saturation point in symmetric nuclear matter once the three hole-line contributions are included in the Brueckner–Bethe–Goldstone expansion without the addition of three-body forces in the nuclear Hamiltonian. The potential is based on a quark model of nucleons and on the quark–quark interaction together with quark exchange processes. These features introduce an intrinsic nonlocality of the nucleon–nucleon interaction. In order to clarify the role of the quark degrees of freedom and of the nonlocality in the saturation, we perform a comparative study of this potential and the traditional meson exchange models, exemplified in the CD-Bonn potential. We find that at the Brueckner–Hartree–Fock approximation, which corresponds to the two hole-line level of approximation, the dominant modification of the nucleon–nucleon interaction with respect to CD-Bonn is incorporated in the s-wave channels, where the quark degrees of freedom should be more relevant, in particular for the short range quark exchange processes. However, when the three hole-line contribution is included, we find that the higher partial waves play a relevant role, mainly in the term that describes the effect of the medium on the off-shell propagation of the nucleon.

Sign in / Sign up

Export Citation Format

Share Document