Implications of occupancy of 2s1/2 state in sd-shell within RMF+BCS approach

2017 ◽  
Vol 26 (11) ◽  
pp. 1750072 ◽  
Author(s):  
G. Saxena ◽  
M. Kumawat ◽  
M. Kaushik ◽  
U. K. Singh ◽  
S. K. Jain ◽  
...  
Keyword(s):  
Mean Field ◽  
The Other ◽  
Magic Numbers ◽  
Neutron Density ◽  
Shell Closure ◽  
Weakly Bound ◽  
Density Profiles ◽  
Relativistic Mean Field ◽  
Structure Formula ◽  
Bubble Structure

We employ the relativistic mean-field plus BCS (RMF+BCS) approach to study the behavior of [Formula: see text]-shell by investigating in detail the single particle energies, and proton and neutron density profiles along with the deformations and radii of even–even nuclei. Emergence of new shell closure, weakly bound structure and most recent phenomenon of bubble structure are reported in the [Formula: see text]-shell. [Formula: see text]C, [Formula: see text]O and [Formula: see text]S are found to have a weakly bound structure due to particle occupancy in 2[Formula: see text] state. On the other hand [Formula: see text]O, [Formula: see text]Ca and [Formula: see text]Si are found with depleted central density due to the unoccupied 2[Formula: see text] state and hence they are the potential candidates of bubble structure. [Formula: see text]C and [Formula: see text]O emerge as doubly magic with [Formula: see text] in accord with the recent experiments and [Formula: see text]S emerges as a new proton magic nucleus with [Formula: see text]. [Formula: see text] and [Formula: see text] are predicted as magic numbers in doubly magic [Formula: see text]O, [Formula: see text]Ca and [Formula: see text]Si, respectively. These results are found in agreement with the recent experiments and have consistent with the other parameters of RMF and other theories.

scholarly journals Novel feature of doubly bubble nuclei in 50 ≤ Z(N) ≤ 82 region along with magicity and weakly bound structure

2020 ◽  
Vol 29 (08) ◽  
pp. 2050068
Author(s):  
M. Kumawat ◽  
G. Saxena ◽  
M. Kaushik ◽  
S. K. Jain ◽  
J. K. Deegwal ◽  
...  
Keyword(s):  
Mean Field ◽  
Central Density ◽  
Neutron Density ◽  
Weakly Bound ◽  
Density Profiles ◽  
Relativistic Mean Field ◽  
Density Depletion ◽  
Shell Closures ◽  
Neutron Density Distribution

In this work, we identify a unique and novel feature of central density depletion in both proton and neutron named as doubly bubble nuclei in [Formula: see text] region. The major role of 2d-3s single-particle (s.p.) states in the existence of halo and bubble nuclei is probed. The occupancy in s.p. state 3s[Formula: see text] leads to the extended neutron density distribution or halo while the unoccupancy results in the central density depletion. By employing the Relativistic Mean-Field (RMF) approach along with NL3* parameter, the separation energies, s.p. energies, pairing energies, proton and neutron density profiles along with deformations of even–even nuclei are investigated. Our results are concise with few other theories and available experimental data. Emergence on new shell closure and the magicity of conventional shell closures are explored systematically in this yet unknown region.

WEAKLY BOUND STRUCTURES, HALOS AND MAGICITY IN NEUTRON RICH NUCLEI

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2589-2592 ◽  
Author(s):  
G. SAXENA ◽  
D. SINGH ◽  
H. L. YADAV ◽  
A. HAGA ◽  
H. TOKI
Keyword(s):  
Single Particle ◽  
Resonant State ◽  
Mean Field ◽  
Magic Number ◽  
Bound State ◽  
Positive Energy ◽  
Magic Numbers ◽  
Weakly Bound ◽  
Relativistic Mean Field ◽  
State Dependent

Inspired by recent measurements indicating proton magic number at Z =14 in the vicinity of 42 Si , we have employed our relativistic mean-field (RMF) plus state dependent BCS approach for the study of even-even nuclei to obtain magic numbers and to look for nuclei exhibiting weakly bound structures and even halo formation. In our RMF+BCS approach the single particle continuum corresponding to the RMF is replaced by a set of discrete positive energy states for the calculations of pairing energy. It is found that in several nuclei the filling in of low lying single particle resonant state with large angular momentum, even before it becomes a bound state, helps to accommodate more neutrons but with extremely small increase in the binding energy. This gives rise to the occurrence of weakly bound system of neutron rich nuclei.

EVOLUTION OF SHELL STRUCTURE IN NUCLEI

2011 ◽  
Vol 20 (08) ◽  
pp. 1663-1675 ◽  
Author(s):  
A. BHAGWAT ◽  
Y. K. GAMBHIR
Keyword(s):  
Shell Structure ◽  
Crucial Role ◽  
Field Model ◽  
Mean Field ◽  
Mass Region ◽  
The Other ◽  
Mean Field Model ◽  
Relativistic Mean Field ◽  
Shell Closures ◽  
Low Mass

Systematic investigations of the pairing and two-neutron separation energies which play a crucial role in the evolution of shell structure in nuclei, are carried out within the framework of relativistic mean-field model. The shell closures are found to be robust, as expected, up to the lead region. New shell closures appear in low mass region. In the superheavy region, on the other hand, it is found that the shell closures are not as robust, and they depend on the particular combinations of neutron and proton numbers. Effect of deformation on the shell structure is found to be marginal.

THE INNER CRUST OF NEUTRON STARS IN RELATIVISTIC MEAN FIELD APPROACH

2008 ◽  
Vol 17 (09) ◽  
pp. 1765-1773 ◽  
Author(s):  
JIGUANG CAO ◽  
ZHONGYU MA ◽  
NGUYEN VAN GIAI
Keyword(s):  
Boundary Conditions ◽  
Neutron Stars ◽  
Mean Field ◽  
Bcs Theory ◽  
Neutron Density ◽  
Field Approach ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Rmf Model

The microscopic properties and superfluidity of the inner crust in neutron stars are investigated in the framework of the relativistic mean field(RMF) model and BCS theory. The Wigner-Seitz(W-S) cell of inner crust is composed of neutron-rich nuclei immersed in a sea of dilute, homogeneous neutron gas. The pairing properties of nucleons in the W-S cells are treated in BCS theory with Gogny interaction. In this work, we emphasize on the choice of the boundary conditions in the RMF approach and superfluidity of the inner crust. Three kinds of boundary conditions are suggested. The properties of the W-S cells with the three kinds of boundary conditions are investigated. The neutron density distributions in the RMF and Hartree-Fock-Bogoliubov(HFB) models are compared.

Nuclear structure and α-decay study of Og isotopes

2019 ◽  
Vol 28 (06) ◽  
pp. 1950041 ◽  
Author(s):  
R. R. Swain ◽  
B. B. Sahu ◽  
P. K. Moharana ◽  
S. K. Patra
Keyword(s):  
Heavy Element ◽  
Mean Field ◽  
Parent Nucleus ◽  
Shell Closure ◽  
Force Parameter ◽  
Α Decay ◽  
Relativistic Mean Field ◽  
Energy Formula ◽  
Text Element ◽  
Rmf Model

We have examined the binding energy, root-mean-square radii and two neutrons separation energies for the recently accepted super-heavy element [Formula: see text] established as Og using the axially deformed relativistic mean field (RMF) model with NL3 force parameter set. The calculation is extended to various isotopes of [Formula: see text] element, starting from [Formula: see text] till [Formula: see text]. The most stable isotope is found to be at [Formula: see text]. Also, the [Formula: see text]-decay energy [Formula: see text] and hence the half-lives [Formula: see text] is carried out by taking three different empirical formulae for the [Formula: see text]-decay chains of [Formula: see text] supporting the possible shell closure at daughter nuclei [Formula: see text] and/ or 184 and at parent nucleus of [Formula: see text] with [Formula: see text].

scholarly journals ENDPOINT OF rp PROCESS USING RELATIVISTIC MEAN FIELD APPROACH AND A NEW MASS FORMULA

2012 ◽  
Vol 21 (08) ◽  
pp. 1250074 ◽  
Author(s):  
CHIRASHREE LAHIRI ◽  
G. GANGOPADHYAY
Keyword(s):  
Mass Formula ◽  
Optical Potential ◽  
Mean Field ◽  
Proton Capture ◽  
Density Profiles ◽  
X Ray ◽  
Field Approach ◽  
Relativistic Mean Field ◽  
Rapid Proton ◽  
Rp Process

Densities from relativistic mean field calculations are applied to construct the optical potential and, hence calculate the endpoint of the rapid proton capture (rp) process. Mass values are taken from a new phenomenological mass formula. Endpoints are calculated for different temperature-density profiles of various X-ray bursters. We find that the rp process can produce significant quantities of nuclei upto around mass 95. Our results differ from existing works to some extent.

A study of nuclear structure for 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery

2017 ◽  
Vol 32 (22) ◽  
pp. 1750117 ◽  
Author(s):  
Ozan Artun
Keyword(s):  
Nuclear Structure ◽  
Mean Field Theory ◽  
Mean Field ◽  
Nuclear Data ◽  
Binding Energies ◽  
Neutron Density ◽  
Neutron Skin ◽  
Relativistic Mean Field ◽  
Proton Charge ◽  
Nuclear Battery

In this paper, we intend to extend the nuclear data of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] nuclei used in nuclear battery technology, because, these nuclei are quite important for space investigations in radioisotope thermoelectric generator (RTG) and for microelectronic technologies in betavoltaic batteries. Therefore, the nuclear structure properties of nuclei such as separation energies, neutron skin thicknesses, proton, charge and neutron density distributions as a function of radius, the root mean square (rms) proton, charge and neutron radii, binding energies per particle, have been investigated by Hartree–Fock with eight different Skyrme forces. The obtained results have been compared with the experimental data in literature and relativistic mean field theory (RMFT) results.

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 294,302120 Nuclei Using the Relativistic Mean-Field Method

1997 ◽  
Vol 12 (23) ◽  
pp. 1727-1736 ◽  
Author(s):  
Raj K. Gupta ◽  
S. K. Patra ◽  
W. Greiner
Keyword(s):  
Mean Field ◽  
Field Method ◽  
Particle Energy ◽  
Binding Energies ◽  
Magic Numbers ◽  
Relativistic Mean Field ◽  
Oscillator Basis ◽  
Field Formalism ◽  
Parameter Dependent ◽  
Closed Shells

We have studied the structure of superheavy nuclei 294,302120 in the framework of a relativistic mean-field formalism, using three different parameter sets (NL1, NL–SH and TM1) in an axially deformed harmonic oscillator basis. The calculated shapes are found to be parameter-dependent, e.g. NL1 parameter set predicts 302120 as a spherical and 294120 a very weakly oblate deformed nucleus whereas NL–SH and TM1 parameter sets predict both the nuclei with strongly prolate/oblate deformed configurations, in their respective ground states. This result, coupled with the calculated single-particle energy spectrum for NL1 parameter set, supports for Z=120 nuclei the spherical magic shell more at N=184 than at N=172. Even for the spherical 302120 nucleus, many new closed shells are predicted and some of the known magic numbers are found absent. Also, the binding energies of the various isotopes of Z=104–111 nuclei are calculated whose comparisons with experimental data favor the NL1 parameter set.

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