scholarly journals Analysis of the binding energies of the Λ- particle in hypernuclei with the RHVT approach and the Gauss potential

2019 ◽  
Vol 18 ◽  
pp. 19
Author(s):  
C. A. Efthimiou ◽  
M. E. Grypeos ◽  
C. G. Koutroulos ◽  
Th. Petridou
Keyword(s):  
Relativistic Quantum ◽  
Binding Energies ◽  
Core Mass ◽  
Least Squares Fit ◽  
Power Series Expansions ◽  
Analytic Expressions ◽  
Particle Potential ◽  
Hypervirial Theorem ◽  
Single Particle Potential

An analysis is carried out mainly of the ground state binding energies of the Λ-particle in hypernuclei with values of the core mass number AC between 15 and 207 (included) using, as far as possible, recent experimental data.Τhe renormalized (non- relativistic) quantum mechanical hypervirial theorem (RHVT) technique is employed in the form of s- power series expansions and a Gauss single particle potential for the motion of a Λ- particle in hypernuclei is used. Not exact analytic solution is known for the Schrödinger eigenvalue problem in this case. Thus, the approximate analytic expressions (AAE) for the energy eigenvalues which are obtained with the RHVT approach and are quite useful as long as the involved dimensionless parameter s is sufficiently small, are compared only with the numerical solution. The potential parameters are determined by a least-squares fit in the framework of the rigid core model for the hypernuclei. A discussion is also made regarding the determination of the renormalization parameter χ.

scholarly journals On a single particle potential for atomic clusters

2020 ◽  
Vol 9 ◽  
pp. 307
Author(s):  
B. A. Kotsos ◽  
Th. E. Liolios ◽  
M. E. Grypeos ◽  
C. G. Koutroulos ◽  
S. E. Massen
Keyword(s):  
Single Particle ◽  
Metal Clusters ◽  
Atomic Clusters ◽  
Energy Eigenvalues ◽  
Valence Electrons ◽  
Analytic Expressions ◽  
Particle Potential ◽  
Single Particle Potential

The single-particle potential V(r) = -Vo[1+(r/K)^β)^-1, which has been proposed in the recent years for atomic (metal) clusters, is studied analytically in the case β = 2. By using perturbation-type techniques, approximate analytic expressions are obtained for the energy eigenvalues and other physically interesting quantities showing the variation of these quantities with the number of valence electrons. The accuracy is tested for Al clusters and is usually very good.

scholarly journals Study of energy quantities for a hyperon in hypernuclei using a single particle potential

2020 ◽  
Vol 1 ◽  
pp. 77
Author(s):  
G. A. Lalazissis ◽  
M. E. Grypeos ◽  
S. E. Massen
Keyword(s):  
Binding Energy ◽  
Single Particle ◽  
Ground State ◽  
Binding Energies ◽  
Potential Models ◽  
Particle Potential ◽  
Single Particle Potential ◽  
Semi Empirical

A single particle hyperon-nucleus potential is adopted for the study of various energy quantities of a hyperon (Y) in hypernuclei.Approximate semi-empirical formulae for the ground state (g.s.) binding energy and for the oscillator spacing hωΛ of a Λ in hypernuclei are proposed. The region of their validity is discussed.The g.s. binding energies of the Ξ- hyperon in the few known Ξ- hypernuclei are also analyzed and a comparison of the volume integrals of the Ξ- nucleon and Λ nucleon potentials |V_{ΞN}I and |V_{ΛΝ)| is made. The value of the ratio γ=V_{ΞΝ}/|V_{ΛN}| is found to be ~0.8. Such a conclusion is also obtained by using in the same way other potential models such as the Woods-Saxon one.

The Deformation Structure of the Nuclei 32S and 36Ar

2017 ◽  
Vol 13 (2) ◽  
pp. 4678-4688
Author(s):  
K. A. Kharroube
Keyword(s):  
Single Particle ◽  
Electric Quadrupole ◽  
Quadrupole Moments ◽  
Moments Of Inertia ◽  
Deformation Structures ◽  
Particle Potential ◽  
Nilsson Model ◽  
Single Particle Potential ◽  
Axes Of Symmetry ◽  
Good Agreement

We applied two different approaches to investigate the deformation structures of the two nuclei S32 and Ar36 . In the first approach, we considered these nuclei as being deformed and have axes of symmetry. Accordingly, we calculated their moments of inertia by using the concept of the single-particle Schrödinger fluid as functions of the deformation parameter β. In this case we calculated also the electric quadrupole moments of the two nuclei by applying Nilsson model as functions of β. In the second approach, we used a strongly deformed nonaxial single-particle potential, depending on Î² and the nonaxiality parameter γ , to obtain the single-particle energies and wave functions. Accordingly, we calculated the quadrupole moments of S32 and Ar36 by filling the single-particle states corresponding to the ground- and the first excited states of these nuclei. The moments of inertia of S32 and Ar36 are then calculated by applying the nuclear superfluidity model. The obtained results are in good agreement with the corresponding experimental data.

scholarly journals Numerical Study of Hydrogen Trapping: Application to an API 5L X60 Steel

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Patricia Castaño-Rivera ◽  
Viviana P. Ramunni ◽  
Pablo Bruzzoni
Keyword(s):  
Hydrogen Permeation ◽  
Numerical Study ◽  
Local Equilibrium ◽  
Binding Energies ◽  
Hydrogen Trapping ◽  
Free Energies ◽  
Least Squares Fit ◽  
Permeation Transient ◽  
C 50 ◽  
Trapping Sites

A numerical finite difference method is developed here to solve the diffusion equation for hydrogen in presence of trapping sites. A feature of our software is that an optimization of diffusion and trapping parameters is achieved via a non linear least squares fit. On the other hand, we have demonstrated that usual electrochemical hydrogen permeation tests are enough to assess hydrogen free energies of trapping in the range of −35 kJ/mol to −70 kJ/mol. These conclusions are obtained by assuming the presence of saturable traps in local equilibrium with hydrogen and are validated by means of simulated permeation and degassing transients. In addition, we check our model performing electrochemical hydrogen permeation tests at 30°C, 50°C, and 70°C, on an API 5L X60 as received steel state to study its trapping and diffusion properties considering only one type of trapping site. The binding energies (ΔG) and the trap densities (N) are determined by fitting the theoretical model to the experimental permeation data. The steel presents a high density of weak traps, |ΔG|<35 KJ/mol, namely, N=1.4×10−5 mol cm−3. Strong trapping sites which alter the shape of the permeation transient are also detected; their ΔG values ranged from 57 to 72 KJ/mol.

The determination of binding energies and preexponential factors: a time resolved HREELS study on Fe(111)/CO2

2004 ◽  
Vol 572 (2-3) ◽  
pp. 355-365 ◽  
Author(s):  
G. Heß ◽  
Ch. Baumgartner ◽  
A. Petkova ◽  
H. Froitzheim
Keyword(s):  
Binding Energies ◽  
Time Resolved
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