scholarly journals The Study of Modified Semi-Empirical Mass Formula (SEMF) by Considering Isospin Effects in Liquid Drop Model

2019 ◽  
Vol 2 ◽  
pp. 153-160
Author(s):  
Sinta Ayu Sakinah ◽  
Eko Tri Sulistyani
Keyword(s):  
Mass Formula ◽  
Liquid Drop ◽  
Experimental Results ◽  
Macroscopic Model ◽  
Model Parameters ◽  
Liquid Drop Model ◽  
Protons And Neutrons ◽  
Symmetry Properties ◽  
K 12 ◽  
Semi Empirical

We do theoretically study of Modified Semi-Empirical Mass Formula (SEMF) based on macroscopic approach in liquid drop model by considering isospin effects. Isospin is one of internal symmetry properties in hadron group, particularly the nucleon multiplet, it represented by SU(2) isospin group. Hadron is a group of elementary particles take place in the strong interaction. The role of strong interactions represents homogeneous nuclear force, interactions between proton-proton (Fpp) , proton-neutron (Fpn), and neutron-neutron (Fnn) are  same. In other words, protons and neutrons are indistinguishable because mass (energy) between protons and neutrons is almost the same, by removing charge between them (charge independent). The dependence of isospin effects on nuclear symmetry term and odd-even (pairing) term  made the formulation of  SEMF should be modificated, in order to obtain nuclear mass and binding energy of a nucleus close to the experimental results. We do two accuracy testing. First, by comparing |Mexp - Mth| for nuclei Pb82208 using SEMF before and after being modified, the result shows that using SEMF before modification the value of |Mexp - Mth|≈ 0,0204 u and for modified SEMF we obtained |Mexp - Mth|≈ 0,0203 u at k=12 . The value of |Mexp - Mth| for modified SEMF is smaller than before modification, it indicates that Modified SEMF is a good formula to calculate the mass of nuclei. Second, by comparing Modified SEMF with other models such as FRDM, HFB-14, and HFB-17 using accuracy parameter in the form of rms deviation   and number of model parameters   ). The results show that rms deviation   decrease 21% to 0,516 and number of model parameters    ) decrease to 15, consists of 13 macroscopic model parameters    and two microscopic model parameters      and �). The value of model parameters was obtained by fitting to experimental results, as a reason it is called semi-empiric.

scholarly journals MODIFIED BETHE–WEIZSÄCKER MASS FORMULA WITH ISOTONIC SHIFT AND NEW DRIPLINES

2005 ◽  
Vol 20 (21) ◽  
pp. 1605-1618 ◽  
Author(s):  
P. ROY CHOWDHURY ◽  
C. SAMANTA ◽  
D. N. BASU
Keyword(s):  
Mass Formula ◽  
Liquid Drop ◽  
Macroscopic Model ◽  
Liquid Drop Model ◽  
Nuclear Masses

Nuclear masses are calculated using the modified Bethe–Weizsäcker mass formula in which the isotonic shifts have been incorporated. The results are compared with the improved liquid drop model with isotonic shift. Mass excesses predicted by this method compares well with the microscopic–macroscopic model while being much more simple. The neutron and proton drip lines have been predicted using this modified Bethe–Weizsäcker mass formula with isotonic shifts.

scholarly journals Modification of the nuclear landscape in the inverse problem framework using the generalized Bethe–Weizsäcker mass formula

2018 ◽  
Vol 27 (02) ◽  
pp. 1850015 ◽  
Author(s):  
S. Cht. Mavrodiev ◽  
M. A. Deliyergiyev
Keyword(s):  
Inverse Problem ◽  
Mass Formula ◽  
Maximum Deviation ◽  
Model Parameters ◽  
Magic Numbers ◽  
Systems Of Equations ◽  
Nonlinear Systems Of Equations ◽  
Nuclear Mass ◽  
Nuclear Masses ◽  
Semi Empirical

We formalized the nuclear mass problem in the inverse problem framework. This approach allows us to infer the underlying model parameters from experimental observation, rather than to predict the observations from the model parameters. The inverse problem was formulated for the numerically generalized semi-empirical mass formula of Bethe and von Weizsäcker. It was solved in a step-by-step way based on the AME2012 nuclear database. The established parametrization describes the measured nuclear masses of 2564 isotopes with a maximum deviation less than 2.6[Formula: see text]MeV, starting from the number of protons and number of neutrons equal to 1.The explicit form of unknown functions in the generalized mass formula was discovered in a step-by-step way using the modified least [Formula: see text] procedure, that realized in the algorithms which were developed by Lubomir Aleksandrov to solve the nonlinear systems of equations via the Gauss–Newton method, lets us to choose the better one between two functions with same [Formula: see text]. In the obtained generalized model, the corrections to the binding energy depend on nine proton (2, 8, 14, 20, 28, 50, 82, 108, 124) and ten neutron (2, 8, 14, 20, 28, 50, 82, 124, 152, 202) magic numbers as well on the asymptotic boundaries of their influence. The obtained results were compared with the predictions of other models.

FISSION BARRIERS WITHIN THE LIQUID DROP MODEL WITH THE SURFACE-CURVATURE TERM

2004 ◽  
Vol 13 (01) ◽  
pp. 107-112 ◽  
Author(s):  
K. POMORSKI ◽  
J. DUDEK
Keyword(s):  
Liquid Drop ◽  
Surface Curvature ◽  
Fission Barrier ◽  
Macroscopic Model ◽  
Liquid Drop Model ◽  
Barrier Heights ◽  
Curvature Term ◽  
Fission Barriers ◽  
The Masses ◽  
Weak Influence

The recently revised liquid drop model (PRC 67(2003) 044316) containing the curvature term reproduces the masses of 2766 experimentally known isotopes having Z≥8 and N≥8 with the r.m.s. deviation equal to 0.698 MeV when the microscopic corrections of Moeller et al. is used. The influence of the congruence energy as well as the compression term on the barrier heights is discussed within this new macroscopic model. The r.m.s. deviation of the fission barrier heights of 40 isotopes with Z≥34 is 1.73 MeV only when deformation-dependent congruence energy is included. The effect of the compression term in the liquid drop energy has rather weak influence on the barrier heights.

A study of alpha-decay using effective liquid drop model

2021 ◽  
Author(s):  
G. R. Sridhara ◽  
H. C. Manjunatha ◽  
N. Sowmya ◽  
P. S. Damodara Gupta
Keyword(s):  
Atomic Number ◽  
Liquid Drop ◽  
Alpha Decay ◽  
Nucl Phys ◽  
Spin Effect ◽  
Liquid Drop Model ◽  
Number Range ◽  
Formation Probability ◽  
Semi Empirical

In this paper, we have made an attempt to analyze the alpha-decay half-lives of in the atomic number range [Formula: see text] by considering an effective liquid drop model. The role of pre-formation probability by including iso-spin effect is included during an evaluation of half-lives. We have also compared the studied alpha-decay half-lives with that of semi-empirical formulae such as Viola Seaborg semi-empirical formulae (VSS) [J. Inorg. Nucl. Chem. 28 (1966) 741; Nucl. Phys. A 848 (2010) 279], Royer formulae [J. Phys. G: Nucl. Part. Phys. 26 (2000) 1149; Phys. Rev. C 101 (2020) 034307] and also with that of the available experiments. From this comparison, it can be concluded that the effective liquid drop model produces an alpha-decay half-lives close to the experiments.

Correlation between fission isomer half-lives and liquid-drop model parameters

1971 ◽  
Vol 165 (2) ◽  
pp. 289-304 ◽  
Author(s):  
V. Metag ◽  
R. Repnow ◽  
P. Von Brentano
Keyword(s):  
Liquid Drop ◽  
Model Parameters ◽  
Liquid Drop Model

THE ART OF PREDICTING NUCLEAR MASSES

2008 ◽  
Vol 17 (supp01) ◽  
pp. 398-411 ◽  
Author(s):  
JORGE G. HIRSCH ◽  
IRVING MORALES ◽  
JOEL MENDOZA-TEMIS ◽  
ALEJANDRO FRANK ◽  
JUAN CARLOS LOPEZ-VIEYRA ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Predictive Model ◽  
Iterative Process ◽  
Short Range ◽  
Mass Formula ◽  
Predictive Power ◽  
Liquid Drop ◽  
Liquid Drop Model ◽  
Nuclear Mass ◽  
Nuclear Masses

A review of recent advances in the theoretical analysis of nuclear mass models and their predictive power is presented. After introducing two tests which probe the ability of nuclear mass models to extrapolate, three models are analyzed in detail: the liquid drop model (LDM), the liquid drop model plus empirical shell corrections (LDMM) and the Duflo–Zuker mass formula (DZ). The DZ model is exhibited as the most predictive model. The Garvey–Kelson mass relations are also discussed. It is shown that their fulfillment probes the consistency of the most commonly used mass formulae, and that they can be used in an iterative process to predict nuclear masses in the neighborhood of nuclei with measured masses, offering a simple and reproducible procedure for short range mass predictions.

scholarly journals The Study of Symmetry Energy in Pasta of Neutron Star From Compressible Liquid Drop Model Approximation

2019 ◽  
Vol 2 ◽  
pp. 61-72
Author(s):  
Eko Tri Sulistyani ◽  
Rizky Ananda
Keyword(s):  
Neutron Star ◽  
Symmetry Energy ◽  
Liquid Drop ◽  
Compressible Liquid ◽  
Bonding Energy ◽  
Liquid Drop Model ◽  
Model Approximation ◽  
Protons And Neutrons ◽  
Seitz Cell ◽  
Neutron Pair

The properties of pasta which is located at the bottom of inner crust from neutron star has been studied by using compressibl e liquid drop model. Compressible liquid drop model is a modified liquid drop model as a density function. Liquid drop model based on assumption that the magnitude of nucleus bonding energy is contribution of surface, Coulomb, volume, symmetry, and proton -neutron pair effect. Pasta of neutron star behaves like liquid crystals (mesomhorpic phase). The top layer of pasta filled by free neutron gas, while in the lowest layer of the pasta is filled by proton-neutron gas. The properties of pasta are observed at temperatures close to zero Kelvin with the assumption that neutron star is on ground state and non accretion. The study of pasta emphasizes on symmetry energy’s influence. Symmetry energy reduces the magnitude of bonding energy of nucleon in the nucleus and it causes nucleon to be more easily released from nucleus. After that, symmetry energy influence the properties of pasta, such as the shape of nucleus that is non spherical (some like plates, rods, and bubbles), the fluctuative values of Wigner-Seitz cell, and uneven distribution of protons and neutrons in the pasta region of neutron star.

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