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.

scholarly journals Non-spherical nucleon clusters in the mantle of a neutron star: CLDM based on Skyrme-type forces

2021 ◽  
Vol 2103 (1) ◽  
pp. 012004
Author(s):  
N A Zemlyakov ◽  
A I Chugunov ◽  
N N Shchechilin
Keyword(s):  
Neutron Star ◽  
Nuclear Matter ◽  
Liquid Drop ◽  
Outer Region ◽  
Spherical Shape ◽  
Baryon Number ◽  
Compressible Liquid ◽  
Liquid Drop Model ◽  
The Core ◽  
Nuclear Clusters

Abstract Neutron stars are superdense compact astrophysical objects. The central region of the neuron star (the core) consists of locally homogeneous nuclear matter, while in the outer region (the crust) nucleons are clustered. In the outer crust these nuclear clusters represent neutron-rich atomic nuclei and all nucleons are bound within them. Whereas in the inner crust some neutrons are unbound, but nuclear clusters still keeps generally spherical shape. Here we consider the region between the crust and the core of the star, so-called mantle, where non-spherical nuclear clusters may exist. We apply compressible liquid drop model to calculate the energy density for several shape types of nuclear clusters. It allows us to identify the most energetically favorable configuration as function of baryon number density. Employing four Skyrme-type forces (SLy4 and BSk24, BSk25, BSk26), which are widely used in the neutron star physics, we faced with strong model dependence of the ground state composition. In particular, in agreement with previous works within liquid drop model, mantle is absent for SLy4 (nuclear spheres directly transit into homogeneous nuclear matter; exotic nuclear shapes do not appear).

scholarly journals Liquid Drop Model for Investigating the Outer Crust of Neutron Star

2019 ◽  
Vol 2 ◽  
pp. 87-91
Author(s):  
Feni Fitrishia ◽  
Eko Tri Sulistyani ◽  
Romy Hanang Setya Budhi
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Total Energy ◽  
Liquid Drop ◽  
Liquid Drop Model ◽  
Model Approximation ◽  
Mass Model ◽  
System Equation ◽  
Long Time ◽  
Outer Crust

The properties of outer crust of cooling neutron star by using Liquid Drop Model approximation has been studied. Th is mass model is used to derive the properties of outer crust of neutron star matter such as total energy of system, equation of state (relationship between pressure and density), and composition of the outer crust. The properties of the outer crust are studied under the assumption that neutron star has created for long time and the matter in neutron star is in its ground state. The composition of the outer crust consists of ions Z arranged in a lattice and free electrons e, so that the total energy of the system consists of three contributions: the mass-energy of the nuclear, the energy of electrons and lattice. The equation of state (the relationship between pressure and density) shows that the pressure increases with increasing density in the outer crust layer. With a simple model based on liquid drop model, it is known that the outer crust is composed of nuclei which are at Z ≈ 20-50, with 56Fe core at the upper layer, and 154Cd core at the lowermost layer of the outer crust.

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 Structure formation in soft nanocolloids: liquid-drop model

Soft Matter ◽  
2018 ◽  
Vol 14 (16) ◽  
pp. 3063-3072 ◽  
Author(s):  
A.-K. Doukas ◽  
C. N. Likos ◽  
P. Ziherl
Keyword(s):  
Structure Formation ◽  
Polymer Brushes ◽  
Liquid Drop ◽  
Star Polymers ◽  
Compressible Liquid ◽  
Liquid Drop Model ◽  
Ordered Structures ◽  
Liquid Drops

Using a model where soft nanocolloids such as spherical polymer brushes and star polymers are viewed as compressible liquid drops, we theoretically explore interactions between such particles and the ordered structures that they form.

Symmetrical shapes of equilibrium for a liquid drop model

1963 ◽  
Vol 46 ◽  
pp. 639-659 ◽  
Author(s):  
V.M. Strutinsky ◽  
N.Ya. Lyashchenko ◽  
N.A. Popov
Keyword(s):  
Liquid Drop ◽  
Liquid Drop Model

scholarly journals Bulk properties of rotating nuclei and the validity of the liquid drop model at finite angular momenta

1999 ◽  
Vol 652 (2) ◽  
pp. 142-163 ◽  
Author(s):  
J. Piperova ◽  
D. Samsoen ◽  
P. Quentin ◽  
K. Bencheikh ◽  
J. Bartel ◽  
...  
Keyword(s):  
Liquid Drop ◽  
Liquid Drop Model ◽  
Bulk Properties ◽  
Angular Momenta ◽  
Rotating Nuclei
Sign in / Sign up

Export Citation Format

Share Document