Study of the dependence of alpha decay half-life on the surface symmetry energy

2020 ◽  
Vol 29 (09) ◽  
pp. 2050070
Author(s):  
S. Nejati ◽  
O. N. Ghodsi
Keyword(s):  
Symmetry Energy ◽  
Half Life ◽  
Surface Region ◽  
Alpha Decay ◽  
Proton Density ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Mother And Daughter ◽  
Energy Coefficient ◽  
Finite Nuclei

In this study, the effect of the surface symmetry energy on the neutron skin thickness and division of it into the bulk and surface parts are investigated by determination of the symmetry energy coefficient [Formula: see text] of finite nuclei. We demonstrate the importance of the isospin asymmetry distribution in the symmetry energy coefficient of finite nuclei at the surface region. We attempt to find out how different surface symmetry energies may affect alpha decay half-life. The Skyrme interactions are used to describe the neutron and proton density distributions and to calculate the symmetry energy coefficient [Formula: see text] of four nuclei and the surface symmetry energy. The chosen Skyrme interactions can produce the binding energy and root-mean-square charge radii of both mother and daughter nuclei. We single out the spherical isotones of [Formula: see text] named [Formula: see text]Pb, [Formula: see text]Po, [Formula: see text]Rn and [Formula: see text]Ra for daughter nuclei and explore the dependence of the bulk and surface contributions on the surface symmetry energy. The half-life of mother nuclei, i.e., [Formula: see text]Po, [Formula: see text]Rn, [Formula: see text]Ra and [Formula: see text]Th, is employed to investigate the extent to which it is affected by different surface symmetry energies. The calculated half-lives show a downward tendency for different surface symmetry energies which can be caused by various neutron skin thicknesses.

Neutron skin thickness of finite nuclei with finite range effective interaction in droplet model

2018 ◽  
Vol 27 (06) ◽  
pp. 1850049 ◽  
Author(s):  
M. Pal ◽  
S. Chakraborty ◽  
B. Sahoo ◽  
S. Sahoo
Keyword(s):  
Symmetry Energy ◽  
Effective Interaction ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Droplet Model ◽  
Density Region ◽  
Neutron Skin Thickness ◽  
Number Formula ◽  
Energy Formula ◽  
Finite Nuclei

We analyze the relation between the symmetry energy coefficient [Formula: see text] of finite nuclei with mass number [Formula: see text] in the semi-empirical mass formula. The nuclear matter symmetry energy [Formula: see text] at reference density [Formula: see text] in the subsaturation density region can be determined by the symmetry energy [Formula: see text] and its density slope [Formula: see text] at the saturation density [Formula: see text]. From this relation, the neutron skin thickness ‘[Formula: see text]’ in finite nuclei with droplet model are correlated to the various symmetry energy parameters. A prominent role of the bulk symmetry energy [Formula: see text] to the so-called surface stiffness coefficient [Formula: see text] is observed in deriving the size of the neutron skin. Two types of neutron skins are distinguished: the “surface” and the “bulk”. The linear dependence of the neutron skin thickness for different stable nuclei ([Formula: see text]) on the slope [Formula: see text] of the symmetry energy as well as on the relative neutron excess [Formula: see text] is observed. Though the value of the surface width is found to be limited within 0.1[Formula: see text]fm, its contribution should not be neglected to measure neutron skin thickness.

scholarly journals Nuclear Symmetry Energy Effects on the Bulk Properties of Neutron-rich Finite Nuclei

2020 ◽  
Vol 27 ◽  
pp. 91
Author(s):  
Manolis Divaris ◽  
Charalampos Moustakidis
Keyword(s):  
Symmetry Energy ◽  
Dominant Role ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Nuclear Symmetry Energy ◽  
Heavy Nuclei ◽  
Isospin Asymmetry ◽  
Asymmetry Function ◽  
Finite Nuclei ◽  
Dependent Interaction

We systematically study the effect of the nuclear symmetry energy in the basic properties of finite, neutron-rich, heavy nuclei where symmetry energy plays a dominant role. We employ a variational method, in the framework of the Thomas-Fermi approximation, to study the effect of the symmetry energy on the neutron skin thickness and symmetry energy coefficients of various nuclei. The isospin asymmetry function a(r) is directly related to the symmetry energy as a consequence of the variational principle. In addition to this, the Coulomb interaction is included in a self-consistent way. The energy density of the asymmetric nuclear matter that is used, has its origins in a momentum-dependent interaction.

Effects of pairing correlations on the neutron skin thickness and the symmetry energy

2017 ◽  
Vol 96 (2) ◽  
Author(s):  
Soonchul Choi ◽  
Ying Zhang ◽  
Myung-Ki Cheoun ◽  
Youngshin Kwon ◽  
Kyungsik Kim ◽  
...  
Keyword(s):  
Symmetry Energy ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Neutron Skin Thickness ◽  
Pairing Correlations

scholarly journals The Equation of State of Nuclear Matter: From Finite Nuclei to Neutron Stars

Universe ◽  
2020 ◽  
Vol 6 (8) ◽  
pp. 119 ◽  
Author(s):  
G. Fiorella Burgio ◽  
Isaac Vidaña
Keyword(s):  
Neutron Star ◽  
Symmetry Energy ◽  
Quantum Monte Carlo ◽  
Equations Of State ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Large Set ◽  
Solar Mass ◽  
Atomic Nuclei ◽  
Neutron Skin Thickness

Background. We investigate possible correlations between neutron star observables and properties of atomic nuclei. In particular, we explore how the tidal deformability of a 1.4 solar mass neutron star, M1.4, and the neutron-skin thickness of 48Ca and 208Pb are related to the stellar radius and the stiffness of the symmetry energy. Methods. We examine a large set of nuclear equations of state based on phenomenological models (Skyrme, NLWM, DDM) and ab initio theoretical methods (BBG, Dirac–Brueckner, Variational, Quantum Monte Carlo). Results: We find strong correlations between tidal deformability and NS radius, whereas a weaker correlation does exist with the stiffness of the symmetry energy. Regarding the neutron-skin thickness, weak correlations appear both with the stiffness of the symmetry energy, and the radius of a M1.4. Our results show that whereas the considered EoS are compatible with the largest masses observed up to now, only five microscopic models and four Skyrme forces are simultaneously compatible with the present constraints on L and the PREX experimental data on the 208Pb neutron-skin thickness. We find that all the NLWM and DDM models and the majority of the Skyrme forces are excluded by these two experimental constraints, and that the analysis of the data collected by the NICER mission excludes most of the NLWM considered. Conclusion. The tidal deformability of a M1.4 and the neutron-skin thickness of atomic nuclei show some degree of correlation with nuclear and astrophysical observables, which however depends on the ensemble of adopted EoS.

scholarly journals Limiting symmetry energy elements from empirical evidence

2017 ◽  
Vol 26 (05) ◽  
pp. 1750022 ◽  
Author(s):  
B. K. Agrawal ◽  
S. K. Samaddar ◽  
J. N. De ◽  
C. Mondal ◽  
Subhranil De
Keyword(s):  
Nuclear Matter ◽  
Symmetry Energy ◽  
Density Functional ◽  
Effective Interaction ◽  
Finite Range ◽  
Energy Density Functional ◽  
Density Dependent ◽  
Bulk Data ◽  
Energy Coefficient ◽  
Finite Nuclei

In the framework of an equation of state (EoS) constructed from a momentum and density-dependent finite-range two-body effective interaction, the quantitative magnitudes of the different symmetry elements of infinite nuclear matter are explored. The parameters of this interaction are determined from well-accepted characteristic constants associated with homogeneous nuclear matter. The symmetry energy coefficient [Formula: see text], its density slope [Formula: see text], the symmetry incompressibility [Formula: see text] as well as the density-dependent incompressibility [Formula: see text] evaluated with this EoS are seen to be in good harmony with those obtained from other diverse perspectives. The higher order symmetry energy coefficients [Formula: see text], etc., are seen to be not very significant in the domain of densities relevant to finite nuclei, but gradually build up at supra-normal densities. The analysis carried out with a Skyrme-inspired energy density functional (EDF) obtained with the same input values for the empirical bulk data associated with nuclear matter yields nearly the same results.

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