DYNAMICS OF DEEPLY BOUND ${\bar K}$ STATES

2007 ◽  
Vol 22 (02n03) ◽  
pp. 633-636 ◽  
Author(s):  
JIŘI MAREŠ ◽  
ELIAHU FRIEDMAN ◽  
AVRAHAM GAL
Keyword(s):  
Binding Energy ◽  
Mean Field ◽  
Binding Energies ◽  
Light Nuclei ◽  
Nucleus Interaction ◽  
Core Nucleus ◽  
Relativistic Mean Field ◽  
The Core ◽  
Wide Range ◽  
Rmf Model

Dynamical effects for [Formula: see text] deeply bound nuclear states are explored within a relativistic mean field (RMF) model. Varying the strength of [Formula: see text] - nucleus interaction, we cover a wide range of binding energies in order to evaluate the corresponding widths. A lower limit [Formula: see text] is placed on the width expected for binding energy in the range of [Formula: see text]. Substantial polarization of the core nucleus is found in light nuclei. We discuss the results of the FINUDA experiment at DAΦNE which presented evidence for deeply bound K- pp states in Li and 12 C .

scholarly journals Microscopic study of higher-order deformation effects on the ground states of superheavy nuclei around Hs-270

2021 ◽  
Author(s):  
Xiao-Qian Wang ◽  
Xiang-Xiang Sun ◽  
Shan-Gui 周善贵 Zhou
Keyword(s):  
Single Particle ◽  
Mean Field ◽  
Higher Order ◽  
Binding Energies ◽  
Superheavy Nuclei ◽  
Effective Interactions ◽  
Relativistic Mean Field ◽  
Order Deformation ◽  
Particle Spectra ◽  
Rmf Model

Abstract We study the effects of higher-order deformations βλ (λ = 4,6,8, and 10) on the ground state properties of superheavy nuclei (SHN) near the deformed doubly magic nucleus 270Hs by using the multidimensionally-constrained (MDC) relativistic mean-field (RMF) model with five effective interactions PC-PK1, PK1, NL3∗, DD-ME2, and PKDD. The doubly magic properties of 270Hs are featured by the large energy gaps at N = 162 and Z = 108 in the single-particle spectra. By investigating the binding energies and single-particle levels of270Hs in multidimensional deformation space, we find that the deformation β6 has the greatest impact on the binding energy among these higher-order deformations and influences the shell gaps considerably. Similar conclusions hold for other SHN near 270Hs. Our calculations demonstrate that the deformation β6 must be considered when studying SHN by using MDC-RMF.

scholarly journals Comparison of perturbative and non-perturbative methods in f(R) gravity

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
K. Nobleson ◽  
Amna Ali ◽  
Sarmistha Banik
Keyword(s):  
Mean Field ◽  
Structure And Properties ◽  
Relativistic Mean Field ◽  
The Core ◽  
Equation Of States ◽  
Mean Field Models ◽  
Perturbative Methods ◽  
Wide Range ◽  
Strange Particles ◽  
Range Of Values

AbstractIn this work, we investigate the structure and properties of neutron stars in $$R^2$$ R 2 gravity using two approaches, viz: the perturbative and non-perturbative methods. For this purpose, we consider NS with several nucleonic, as well as strange EoS generated in the framework of relativistic mean field models. The strange particles in the core of NS are in the form of $$\Lambda $$ Λ hyperons and quarks, in addition to the nucleons and leptons. In both the approaches, we obtain mass–radius relation for a wide range of values of the extra degree of freedom parameter a arising due to modification of gravity at large scales. The mass–radius relation of the chosen equation of states lies well within the observational limit in the case of GR. We identify the changes in the property of neutron star in the background of f(R) gravity, and compare the results in both the methods. We also identify the best suited method to study the modified gravity using the astrophysical observations.

Search for exotic features in the ground state light nuclei with 10 ≤Z ≤ 18 from stable valley to drip lines

2019 ◽  
Vol 28 (11) ◽  
pp. 1950101
Author(s):  
G. Saxena ◽  
M. Kumawat ◽  
Mamta Aggarwal
Keyword(s):  
Mean Field ◽  
Form Factors ◽  
Binding Energies ◽  
Light Nuclei ◽  
Neutron Skin ◽  
Weakly Bound ◽  
Relativistic Mean Field ◽  
State Dependent ◽  
Prolate Shape ◽  
Neutron Rich Isotopes

We present a systematic description of the exotic features in the ground states of light nuclei from the stable valley to the drip lines. A study with the even and odd isotopes of Ne, Mg, Si, S and Ar has been performed using theoretical formalisms (i) Relativistic mean-field plus state-dependent BCS approach and (ii) Macroscopic–Microscopic (MM) approach using the triaxially deformed Nilsson–Strutinsky Method. The computed binding energies and one- and two-neutron separation energies using both the theories show magic character of [Formula: see text] and 40. The neutron and proton radii and the neutron densities show a well-developed neutron skin in the neutron-rich isotopes. The exotic phenomena such as weakly bound structures and the central density depletion characterized as bubble effect are explored. Our calculations for the single particle levels, density profiles and the charge form factors indicate bubble-like structures. Few new candidates of bubble nuclei are identified. Most of the nuclei in this region are found deformed with mostly prolate shape and few triaxial shapes while many nuclei exhibit the phenomenon of shape coexistence. Our results display a reasonable agreement between both the theories and the available experimental data.

STRUCTURE OF LIGHT NUCLEI IN RELATIVISTIC MEAN FIELD THEORY

1993 ◽  
Vol 02 (02) ◽  
pp. 471-477 ◽  
Author(s):  
S.K. PATRA
Keyword(s):  
Field Theory ◽  
Field Model ◽  
Mean Field Theory ◽  
Mean Field ◽  
Binding Energies ◽  
Experimental Results ◽  
Light Nuclei ◽  
Mean Field Model ◽  
Bulk Properties ◽  
Relativistic Mean Field

Bulk properties such as the binding energies and rms radii are calculated for some light (Z=1−8) nuclei using deformed relativistic mean-field model. Severe discrepancy between the calculated and experimental results are pointed out for the very light nuclei. We discuss possible causes of discrepancy for very light nuclei.

scholarly journals ${\bar K}$-NUCLEAR DEEPLY BOUND STATES?

2007 ◽  
Vol 16 (03) ◽  
pp. 891-903
Author(s):  
AVRAHAM GAL
Keyword(s):  
Bound States ◽  
Decay Channel ◽  
Matter Density ◽  
Binding Energies ◽  
Light Nuclei ◽  
Nuclear Level ◽  
Core Nucleus ◽  
Nuclear Matter Density ◽  
The Core ◽  
Energy Dependent

Following the prediction by Akaishi and Yamazaki of relatively narrow [Formula: see text]-nuclear states, deeply bound by over 100 MeV where the main decay channel [Formula: see text] is closed, several experimental signals in stopped K- reactions on light nuclei have been interpreted recently as due to such states. In this talk I review (i) the evidence from K--atom data for a deep[Formula: see text]-nucleus potential, as attractive as [Formula: see text] at nuclear matter density, that could support such states; and (ii) the theoretical arguments for a shallow potential, [Formula: see text]. I then review a recent work by Mareš, Friedman and Gal in which [Formula: see text]-nuclear bound states are generated dynamically across the periodic table, using a RMF Lagrangian that couples the [Formula: see text] to the scalar and vector meson fields mediating the nuclear interactions. The reduced phase space available for [Formula: see text] absorption from these bound states is taken into account by adding a density- and energy-dependent imaginary term, underlying the corresponding [Formula: see text]-nuclear level widths, with a strength constrained by K--atom fits. Substantial polarization of the core nucleus is found for light nuclei, with central nuclear densities enhanced by almost a factor of two. The binding energies and widths calculated in this dynamical model differ appreciably from those calculated for a static nucleus. These calculations provide a lower limit of [Formula: see text] on the width of nuclear bound states for [Formula: see text] binding energy in the range [Formula: see text].

scholarly journals ENERGY SYSTEMATICS OF HEAVY NUCLEI — MEAN FIELD MODELS IN COMPARISON

2011 ◽  
Vol 20 (06) ◽  
pp. 1379-1390 ◽  
Author(s):  
P.-G. REINHARD ◽  
B. K. AGRAWAL
Keyword(s):  
Mean Field ◽  
Binding Energies ◽  
Superheavy Nuclei ◽  
Heavy Nuclei ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Mean Field Models ◽  
Opposite Trend ◽  
Super Heavy Nuclei ◽  
Rmf Model

We compare the systematics of binding energies computed within the standard and extended versions of the relativistic mean-field (RMF) model and the Skyrme–Hartree–Fock (SHF) model. The general trends for the binding energies for super-heavy nuclei are significantly different for these models. The SHF models tend to underbind the superheavy nuclei, while RMF models show just the opposite trend. The extended RMF model seems to provide remarkable improvements over the results obtained for the standard RMF model.

scholarly journals np-Pair Correlations in the Isovector Pairing Model

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1405
Author(s):  
Feng Pan ◽  
Yingwen He ◽  
Lianrong Dai ◽  
Chong Qi ◽  
Jerry P. Draayer
Keyword(s):  
Binding Energy ◽  
Occupation Number ◽  
Mean Field ◽  
Energy Difference ◽  
Binding Energies ◽  
Pair Correlations ◽  
Isospin Symmetry Breaking ◽  
Pairing Model ◽  
Proton Pairing ◽  
Spin Basis

A diagonalization scheme for the shell model mean-field plus isovector pairing Hamiltonian in the O(5) tensor product basis of the quasi-spin SUΛ(2) ⊗ SUI(2) chain is proposed. The advantage of the diagonalization scheme lies in the fact that not only can the isospin-conserved, charge-independent isovector pairing interaction be analyzed, but also the isospin symmetry breaking cases. More importantly, the number operator of the np-pairs can be realized in this neutron and proton quasi-spin basis, with which the np-pair occupation number and its fluctuation at the J = 0+ ground state of the model can be evaluated. As examples of the application, binding energies and low-lying J = 0+ excited states of the even–even and odd–odd N∼Z ds-shell nuclei are fit in the model with the charge-independent approximation, from which the neutron–proton pairing contribution to the binding energy in the ds-shell nuclei is estimated. It is observed that the decrease in the double binding-energy difference for the odd–odd nuclei is mainly due to the symmetry energy and Wigner energy contribution to the binding energy that alter the pairing staggering patten. The np-pair amplitudes in the np-pair stripping or picking-up process of these N = Z nuclei are also calculated.

TABLE OF GROUND STATE PROPERTIES OF NUCLEI IN THE RMF MODEL

2013 ◽  
Vol 28 (16) ◽  
pp. 1350068 ◽  
Author(s):  
TUNCAY BAYRAM ◽  
A. HAKAN YILMAZ
Keyword(s):  
Ground State ◽  
Mean Field ◽  
Properties Of Nuclei ◽  
Relativistic Mean Field ◽  
Ground State Properties ◽  
Pairing Correlations ◽  
Ground State Energies ◽  
Rmf Model

The ground state energies, sizes and deformations of 1897 even–even nuclei with 10≤Z ≤110 have been carried out by using the Relativistic Mean Field (RMF) model. In the present calculations, the nonlinear RMF force NL3* recent refitted version of the NL3 force has been used. The BCS (Bardeen–Cooper–Schrieffer) formalism with constant gap approximation has been taken into account for pairing correlations. The predictions of RMF model for the ground state properties of some nuclei have been discussed in detail.

RELATIVISTIC MEAN FIELD THEORETICAL FOUNDATION OF THE DROPLET MODEL FOR NUCLEI

2002 ◽  
Vol 11 (01) ◽  
pp. 55-65 ◽  
Author(s):  
CHUN-YUAN GAO ◽  
QI-REN ZHANG
Keyword(s):  
Mass Formula ◽  
Energy Surface ◽  
Theoretical Foundation ◽  
Mean Field Theory ◽  
Mean Field ◽  
Binding Energies ◽  
Droplet Model ◽  
Relativistic Mean Field ◽  
Theoretical Foundations ◽  
Type Mass

The binding energies per-nucleon for 1654 nuclei, whose mass numbers range from 16 to 263 and charge numbers range from 8 to 106, are calculated by the relativistic mean field theory, with finite nucleon size effect being taken into account. The calculated energy surface goes through the middle of experimental points, and the root mean square deviation for the binding energies per-nucleon is 0.08163 MeV. The numerical results may be well simulated by a droplet model type mass formula. The droplet model is therefore put on the relativistic mean field theoretical foundations.

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