Systematic study of the effect of short range correlations on the form factors and densities of s-p-d shell nuclei

Analytical expressions of the one- and two-body terms in the cluster expansion of the charge form factors and densities of the s-p and s-d shell nuclei with N=Z are derived. They depend on the harmonic oscillator parameter 6 and the parameter β which originates from the Jastrow correlation function. These expressions are used for the systematic study of the effect of short range correlations on the form factors and densities and of the mass dependence of the parameters ò and β. These parameters have been determined by fit to the experimental charge form factors. The inclusion of the correlations reproduces the experimental charge form factors at the high momentum transfers (q > 2 fm^-1). It is found that while the parameter β is almost constant for the closed shell nuclei, 4He, 16O and 40Ca, its values are larger (less correlated systems) for the open shell nuclei, indicating a shell effect in the closed shell nuclei.

One-body density matrix and momentum distribution in s-p and s-d shell nuclei

Analytical expressions of the one- and two- body terms in the cluster expansion of the one-body density matrix and momentum distribution of the s-p and s-d shell nuclei with Ν — Ζ are derived. They depend on the harmonic oscillator parameter b and the parameter β which originates from the Jastrow correlation function. These parameters have been determined .by least squares fit to the experimental charge form factors. The inclusion of short-range correlations increases the high momentum component of the momentum distribution, 7i(k) for all nuclei we have considered while there is an A dependence of ra(k) both at small values of k and the high momentum component. The A dependence of the high momentum com- . ponent of n(k) becomes quite small when the nuclei 24Mg, 28Si and 32S are treated as ld-2s shell nuclei having the occupation probability of the 2s-state as an extra free parameter in the fit to the form factors

Optical Dispersion Characterization of Sprayed Zn1-xMnxO Thin Films

Uniform and adherent Zn1-xMnxO films have been deposited by using spray pyrolysis technique on glass substrates. The optical properties and dispersion parameters of zinc oxide have been studied as a function of doping concentration with Mn. Changes in direct optical energy band gap of cobalt oxide films were confirmed after doping, the optical energy gap Eg increased from 3.13 eV for the undoped ZnO to 3.39 eV with increasing the doping concentration of Mn to 4%. The changes in dispersion parameters and Urbach tails were investigated. An increase in the doping concentration causes a decrease in the average oscillator strength. The single-oscillator parameter has been reported.

Study of Nuclei with A = 5 on the Basis of the Unitary Scheme Model

The total antisymmetric wave functions of the different states of nuclei with A = 5 are calculated by using the basis of the unitary scheme model corresponding to numbers of quanta of excitations N = 1, 2, 3, 4, 5, 6, and 7. The residual interactions used in these calculations are the Gogny et al. potential, the Doma et al. Potential, and an effective interaction which has been used successfully for the nucleus 6Li. The energy matrices for nuclei with A = 5 are diagonalized in terms of the oscillator parameter ℏω, which is varied in order to obtain the best fit to the spectra of these nuclei. The binding energy, the root mean-square radius, and the magnetic dipole moment of 5He are also calculated. Some new levels for these nuclei are obtained. The role of the three-body forces is also investigated for the nucleus 5He.

Quantum Entropy for Nuclei

The position- and momentum-space information entropies of nuclei are calculated in the framework of two models of the nucleus, i.e. the harmonic oscillator shell model and a correlated model which takes into account short range correlations. It is found that for every nucleus the sum of position and momentum entropies is independent of the oscillator parameter and increases slightly by introducing short range correlations. Finally it turns out that the same functional form S =aN + bN ln N for the entropy as function of the number of particles N (electrons or nucleons) holds approximately for atomic and nuclear systems.