scholarly journals A relativistic mean field study of multi-strange system

2014 ◽  
Vol 23 (09) ◽  
pp. 1450052 ◽  
Author(s):  
M. Ikram ◽  
S. K. Singh ◽  
A. A. Usmani ◽  
S. K. Patra
Keyword(s):  
Mean Field ◽  
Heavy Ion ◽  
Mass Region ◽  
Binding Energies ◽  
Spin Orbit ◽  
Strong Decay ◽  
Relativistic Mean Field ◽  
Orbit Potential ◽  
Bubble Structure ◽  
The Stability

In this paper, we study the binding energies, radii, single-particle energies, spin-orbit potential and density profile for multi-strange hypernuclei in the range of light mass to superheavy mass region within the relativistic mean field (RMF) theory. The stability of multi-strange hypernuclei as a function of introduced hyperons (Λ and Σ) is investigated. The neutron, lambda and sigma mean potentials are presented for light to superheavy hypernuclei. The inclusion of hyperons affects the nucleon, lambda and sigma spin-orbit potentials significantly. The bubble structure of nuclei and corresponding hypernuclei is studied. Nucleon and lambda halo structures are also investigated. A large class of bound multi-strange systems formed from the combination of nucleons and hyperons (n, p, Λ, Σ+ and n, p, Λ, Σ-) is suggested in the region of superheavy hypernuclei which might be stable against the strong decay. These multi-strange systems might be produced in heavy-ion reactions.

GROUND STATE PROPERTIES OF EXTREME NEUTRON RICH ISOTOPES OBSERVED: A RELATIVISTIC MEAN FIELD APPROACH

2011 ◽  
Vol 20 (11) ◽  
pp. 2293-2303 ◽  
Author(s):  
PROVASH MALI
Keyword(s):  
Ground State ◽  
Mean Field ◽  
Mass Region ◽  
Binding Energies ◽  
Droplet Model ◽  
Shell Effects ◽  
Relativistic Mean Field ◽  
Ground State Properties ◽  
Neutron Rich Isotopes ◽  
Good Agreement

The ground state properties namely the binding energy, the root mean square (rms) radius (neutron, proton and charge) and the deformation parameter of 45 newly identified neutron-rich isotopes in the A~71–152 mass region have been predicted in the relativistic mean filed (RMF) framework along with the Bardeen–Cooper–Schrieffer (BCS) type of pairing. Validity of the RMF results with the NL3 effective force are tested for odd-A Zn and Rh isotopic chains without taking the time reversal symmetry breaking effects into consideration. The RMF prediction on the binding energies are in good agreement with the empirical/finite-range droplet model calculation. The shell effects on the rms radii of odd-A Zn and Rh isotopes are nicely reproduced. The possibility of shape-coexistence in the newly identified nuclei is discussed.

AN INVESTIGATION OF THE NUCLEAR STRUCTURES OF EVEN–EVEN NEUTRON-RICH Sr, Zr AND Mo ISOTOPES

2013 ◽  
Vol 28 (05) ◽  
pp. 1350007 ◽  
Author(s):  
HÜSEYIN AYTEKIN ◽  
OZAN ARTUN
Keyword(s):  
Field Theory ◽  
Mean Field Theory ◽  
Mean Field ◽  
Mass Region ◽  
Skyrme Force ◽  
Binding Energies ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Nuclear Structures ◽  
Mo Isotopes

Binding energies and their differences are investigated to evaluate the two-neutron separation energies (S2n), the two-proton separation energies (S2p) and the average proton–neutron interaction strengths (δVpn) of neutron-rich Sr , Zr and Mo isotopes in the mass region A = 86–110, including even–even nuclei. Calculations were performed using the Hartree–Fock–Bogoliubov (HFB) method with different Skyrme force parametrizations. The obtained results are discussed and compared with the results of experimental and relativistic mean-field theory (RMFT).

DECREASE OF THE SPIN-ORBIT INTERACTION IN DRIP-LINE NUCLEI, USING RELATIVISTIC MEAN FIELD MODELS

2006 ◽  
Vol 15 (05) ◽  
pp. 1149-1155 ◽  
Author(s):  
M. S. MEHTA ◽  
B. K. SHARMA ◽  
S. K. PATRA ◽  
RAJ K. GUPTA ◽  
W. GREINER
Keyword(s):  
Field Model ◽  
Mean Field ◽  
Neutron Number ◽  
Effective Field ◽  
Drip Line ◽  
Energy Splitting ◽  
Spin Orbit ◽  
Mean Field Model ◽  
Relativistic Mean Field ◽  
Orbit Potential

The spin-orbit potential and the energy splitting of spin-orbit partners in nuclei towards the neutron drip-line are found to show the decreasing behavior with the increase of neutron number, in both the spherical and deformed versions of the standard relativistic mean field model, the SRMF and DRMF, and its extended version for spherical case, the effective field theory motivated relativistic mean field model, the E-RMF. The calculations are presented for nuclei in different mass regions, which include the isotopes of F , Mg , Sb , Pb and Bi 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.

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.

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 Impact of the Nuclear Equation of State on the Stability of Hybrid Neutron Stars

Universe ◽  
2019 ◽  
Vol 5 (8) ◽  
pp. 186 ◽  
Author(s):  
Mateusz Cierniak ◽  
Tobias Fischer ◽  
Niels-Uwe Bastian ◽  
Thomas Klähn ◽  
Marc Salinas
Keyword(s):  
Equations Of State ◽  
Mean Field Theory ◽  
Mean Field ◽  
Type Model ◽  
Two Phase ◽  
Relativistic Mean Field ◽  
Nuclear Equation Of State ◽  
Hot Matter ◽  
The Stability ◽  
Quark Phase

We construct a set of equations of state (EoS) of dense and hot matter with a 1st order phase transition from a hadronic system to a deconfined quark matter state. In this two-phase approach, hadrons are described using the relativistic mean field theory with different parametrisations and the deconfined quark phase is modeled using vBag, a bag–type model extended to include vector interactions as well as a simultaneous onset of chiral symmetry restoration and deconfinement. This feature results in a non–trivial connection between the hadron and quark EoS, modifying the quark phase beyond its onset density. We find that this unique property has an impact on the predicted hybrid (quark core) neutron star mass–radius relations.

TWO-OSCILLATOR BASIS EXPANSION FOR THE SOLUTION OF RELATIVISTIC MEAN FIELD EQUATIONS

2000 ◽  
Vol 09 (06) ◽  
pp. 507-520
Author(s):  
S. V. S. SASTRY ◽  
ARUN K. JAIN ◽  
Y. K. GAMBHIR
Keyword(s):  
Ground State ◽  
Mean Field ◽  
Surface Region ◽  
Binding Energies ◽  
Basis Functions ◽  
Field Equations ◽  
Basis Expansion ◽  
Relativistic Mean Field ◽  
Mean Field Equations ◽  
Spherical Nuclei

In the relativistic mean field (RMF) calculations usually the basis expansion method is employed. For this one uses single harmonic oscillator (HO) basis functions. A proper description of the ground state nuclear properties of spherical nuclei requires a large (around 20) number of major oscillator shells in the expansion. In halo nuclei where the nucleons have extended spatial distributions, the use of single HO basis for the expansion is inadequate for the correct description of the nuclear properties, especially that of the surface region. In order to rectify these inadequacies, in the present work an orthonormal basis composed of two HO basis functions having different sizes is proposed. It has been shown that for a typical case of (A=11) the ground state constructed using two-HO wave functions extends much beyond the second state or even third excited state of the single HO wave function. To demonstrate its usefulness explicit numerical RMF calculations have been carried out using this procedure for a set of representative spherical nuclei ranging from 16 O to 208 Pb . The binding energies, charge radii and density distributions have been correctly reproduced in the present scheme using a much smaller number of major shells (around 10) in the expansion.

scholarly journals Effects of symmetry energy on the radius and tidal deformability of neutron stars in the relativistic mean-field model

2020 ◽  
Vol 2020 (4) ◽  
Author(s):  
Jinniu Hu ◽  
Shishao Bao ◽  
Ying Zhang ◽  
Ken’ichiro Nakazato ◽  
Kohsuke Sumiyoshi ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Symmetry Energy ◽  
Binary Star ◽  
Mean Field ◽  
Mass Region ◽  
Saturation Density ◽  
Coupling Constants ◽  
Mean Field Model ◽  
Relativistic Mean Field ◽  
The Family

Abstract The radii and tidal deformabilities of neutron stars are investigated in the framework of the relativistic mean-field (RMF) model with different density-dependent behaviors of symmetry energy. To study the effects of symmetry energy on the properties of neutron stars, $\omega$ meson and $\rho$ meson coupling terms are included in a popular RMF Lagrangian, i.e., the TM1 parameter set, which is adopted for the widely used supernova equation of state (EoS) table. The coupling constants relevant to the vector–isovector meson, $\rho$, are refitted by a fixed symmetry energy at subsaturation density and its slope at saturation density, while other coupling constants remain the same as the original ones in TM1 so as to update the supernova EoS table. The radius and mass of maximum neutron stars are not so sensitive to the symmetry energy in these family TM1 parameterizations. However, the radii in the intermediate-mass region are strongly correlated with the slope of symmetry energy. Furthermore, the dimensionless tidal deformabilities of neutron stars are also calculated within the associated Love number, which is related to the quadrupole deformation of the star in a static external tidal field and can be extracted from the observation of a gravitational wave generated by a binary star merger. We find that its value at $1.4 \mathrm{M}_\odot$ has a linear correlation to the slope of symmetry energy, unlike that previously studied. With the latest constraints of tidal deformabilities from the GW170817 event, the slope of symmetry energy at nuclear saturation density should be smaller than $60$ MeV in the family TM1 parameterizations. This fact supports the usage of a lower symmetry energy slope for the updated supernova EoS, which is applicable to simulations of neutron star mergers. Furthermore, an analogous analysis is also done within the family IUFSU parameter sets. It is found that the correlations between the symmetry energy slope with the radius and tidal deformability at $1.4 \mathrm{M}_\odot$ have very similar linear relations in these RMF models.

Sign in / Sign up

Export Citation Format

Share Document