Nuclear Spectra in the 1f7/2 Shell

1973 ◽  
Vol 51 (19) ◽  
pp. 2086-2091 ◽  
Author(s):  
François Brut
Keyword(s):  
Spherical Shell ◽  
Least Squares ◽  
Shell Model ◽  
Configuration Space ◽  
Effective Interaction ◽  
Energy Spectra ◽  
Least Squares Fitting ◽  
Fitting Procedure ◽  
Inert Core ◽  
Good Agreement

Energy spectra of nuclei of masses 43 through 53 have been studied. Within the framework of the spherical shell model, we have assumed an “inert" core of 40Ca plus Z − 20 protons and N − 20 neutrons in the lf7/2 shell. With the assumption of pure configurations, two residual interactions have been investigated by treating them exactly for all states. We have first used the “realistic" effective interaction of Kuo and Brown. We have also taken the effective interaction of Dieperink and Brussaard which has been determined in a least-squares fitting procedure. Calculated low-lying states of these nuclei are in good agreement with experimental levels. Among all results, only those for 46Sc, 47V, 48Ti, and 48Cr nuclei are reported here. Some discrepancies, which arise in particular from the restriction we have made for the configuration space, remain.

The Accuracy of Timing the Minima of Eclipsing Variables

1987 ◽  
Vol 7 (2) ◽  
pp. 117-118
Author(s):  
Z. Kviz ◽  
A. P. S. Wong
Keyword(s):  
Least Squares ◽  
Variable Stars ◽  
Magnitude Scale ◽  
Least Squares Fitting ◽  
Eclipsing Variable Stars ◽  
Fitting Procedure ◽  
Linear Intensity

AbstractIt is shown that for the eclipsing variable stars MP Mus and SV Cen a least squares fitting procedure is more accurate when a linear (intensity) rather than a logarithmic (magnitude) scale is used.

Nonlinear least-squares fitting procedure for solid-state NMR powder patterns

1992 ◽  
Vol 4 (3) ◽  
pp. 205-226 ◽  
Author(s):  
Ae Ja Kim ◽  
Leslie G. Butler
Keyword(s):  
Solid State ◽  
Least Squares ◽  
Solid State Nmr ◽  
Nonlinear Least Squares ◽  
Least Squares Fitting ◽  
Fitting Procedure

Further results relating to the electronic spectrum of 175Lu16O

1986 ◽  
Vol 64 (3) ◽  
pp. 246-251 ◽  
Author(s):  
A. Bernard ◽  
C. Effantin
Keyword(s):  
Least Squares ◽  
Electronic Spectrum ◽  
Ground State ◽  
Rotational Analysis ◽  
Least Squares Fitting ◽  
Fitting Procedure ◽  
Vibrational Levels ◽  
Unique Band ◽  
Π State ◽  
New System

Further results are presented concerning the three known systems of the molecule LuO; i.e., A2Π, B2Π, C2Σ+ → X2Σ+. The observed wavenumbers in each of the 12 analyzed bands are reduced using an iterative, least squares fitting procedure. Rotational constants are given for vibrational levels ν = 0 and 1 in the C state and up to ν = 7 in the X and B states. The 1–1 band of the A → X system is partly analyzed. These new calculations confirm level B to be the 3/2 component of a 2Π state; but they give no such confirmation for the identification of the A level, whose 2Π nature is well established, as the 1/2 component of the same state.Moreover, a unique band at 5120 Å that cannot be classified into any of the three known systems is described and attributed to a new system of LuO. A partial rotational analysis is made showing that the band corresponds to a transition involving the level ν = 0 in the ground state. The nature of the upper state is discussed.

scholarly journals A recursive bifurcation model for early forecasting of COVID-19 virus spread in South Korea and Germany

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Julia Shen
Keyword(s):  
South Korea ◽  
Least Squares ◽  
Nonlinear Least Squares ◽  
Future Research ◽  
Logistic Growth ◽  
Virus Spread ◽  
Least Squares Fitting ◽  
Fitting Procedure ◽  
Logistic Growth Model ◽  
Fitting In

AbstractEarly forecasting of COVID-19 virus spread is crucial to decision making on lockdown or closure of cities, states or countries. In this paper we design a recursive bifurcation model for analyzing COVID-19 virus spread in different countries. The bifurcation facilitates recursive processing of infected population through linear least-squares fitting. In addition, a nonlinear least-squares fitting procedure is utilized to predict the future values of infected populations. Numerical results on the data from two countries (South Korea and Germany) indicate the effectiveness of our approach, compared to a logistic growth model and a Richards model in the context of early forecast. The limitation of our approach and future research are also mentioned at the end of this paper.

scholarly journals Statistical Fluctuations of Energy Spectra in the Isobar A = 68 Nuclei

2021 ◽  
pp. 496-504
Author(s):  
Adel. K. Hamoudi ◽  
Hayder A. Abd Alabas
Keyword(s):  
Shell Model ◽  
Matrix Theory ◽  
Energy Spectra ◽  
Nuclear Excitation ◽  
Excitation Energies ◽  
Gaussian Shape ◽  
Model Calculations ◽  
Level Densities ◽  
Statistical Fluctuations ◽  
Inert Core

Statistical fluctuations of nuclear energy spectra for the isobar A = 68 were examined by means of the random matrix theory together with the nuclear shell model. The isobar A = 68 nuclei are suggested to consist of an inert core of 56Ni with 12 nucleons in f5p-space (2p3/2, 1f5/2 and 2p1/2 orbitals). The nuclear excitation energies, required by this work, were obtained through performing f5p-shell model calculations using the isospin formalism f5pvh interaction with realistic single particle energies. All calculations of the present study were conducted using the OXBASH code. The calculated level densities were found to have a Gaussian shape. The distributions of level spacing P(s) and  statistic for the considered classes of states, obtained with full Hamiltonian of f5pvh (absence of the off-diagonal Hamiltonian) calculations, showed a chaotic (regular) behavior and coincided well with the distribution of Gaussian orthogonal ensemble (Poisson). Moreover, these distributions were independent of spin (J) and isospin (T)

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