Full 0homega shell model calculation of the binding energies of the 1f7/2 nuclei (original) (raw)

Shell-model calculations for upper pf-shell nuclei with an effective interaction

EPJ Web of Conferences

Results obtained for the energy spectra and the low-lying positive-parity energy eigenstates of the upper p f-shell nuclei 64 Ge and 68 Se with the use of the effective interaction JUN45 are reported. We address the question of how appropriate is the possibility to construct a symmetry-adapted shell model in a single oscillator shell using a Pairing-plus-Quadrupole Hamiltonian. Specifically, we study the goodness of the symmetries pseudo SU(3) and O(6) in the structure of the energy eigenstates. Finally, we relate our results to a proposed mixed-symmetry approach which is able to simultaneously account for the presence of both the pairing and the quadrupole modes as the most important ingredients in the effective interaction while using a restricted part of the full model space.

New effective interactions for the 0f1p shell

Nuclear Physics A, 1991

New two-body interactions are derived for nuclei in the lower part of the Oflp shell by fitting semi-empirical potential forms and two-body matrix elements to 61 binding and excitation energy data in the mass range 41 to 49. The shell-model calculations assumed a ?a core and valence nucleons distributed over the fuil fp space. Care was taken to exclude intruder states from the selected data set. The r.m.s. deviations between fitted and experimental energies of 176 keV have been achieved by varying only 6 two-body parameters and 4 single-particle energies in the method utilizing a modified surface one-boson exchange potential (MSOBEP) form. in an alternative fit an r.m.s. deviation of 163 keV has been obtained by fitting 12 linear combinations of single-particle energies and two-body matrix elements, while constraining the remaining two-body matrix elements to values of a G-matrix interaction. The results are comparable in quality to recent similar fits in the 1sOd shell. The effects of a mass dependence of the two-body matrix elements are also investigated. An excellent reproduction of ground-state magnetic moments and quadrupole moments is obtained with the new interactions. * The scale of the matrix elements in fig. 2 of ref. 33) should be reduced by three and the scale of the matrix elements in figs. 3 and 4 should be divided by four.

Full pf shell model study of A=48 nuclei

Physical Review C, 1994

Exact diagonalizations with a minimally modified realistic force lead to detailed agreement with measured level schemes and electromagnetic transitions in 48^{48}48Ca, 48^{48}48Sc, 48^{48}48Ti, 48^{48}48V, 48^{48}48Cr and 48^{48}48Mn. Gamow-Teller strength functions are systematically calculated and reproduce the data to within the standard quenching factor. Their fine structure indicates that fragmentation makes much strength unobservable. As a by-product, the calculations suggest a microscopic description of the onset of rotational motion. The spectroscopic quality of the results provides strong arguments in favour of the general validity of monopole corrected realistic forces, which is discussed.

Nuclear binding energies: global collective structures and local shell-model correlations

2003

Nuclear binding energies and two-neutron separation energies are analysed starting from the liquid-drop model and the nuclear shell model in order to describe the global trends of the above observables. We subsequently concentrate on the Interacting Boson Model (IBM) and discuss a new method in order to provide a consistent description of both, ground-state and excitedstate properties. We address the artefacts that appear when crossing midshell using the IBM formulation and perform detailed numerical calculations for nuclei situated in the 50−82 shell. We also concentrate on local deviations from the above global trends in binding energy and two-neutron separation energies that appear in the neutron-deficient Pb region. We address possible effects on the binding energy, caused by mixing of low-lying 0 + intruder states into the ground state, using configuration mixing in the IBM framework. We also study ground-state properties using a macroscopic-microscopic * Postdoctoral fellow of the Fund for Scientific Research-Flanders (Belgium). † Visiting postdoctoral fellow of the Fund for Scientific Research-Flanders (Belgium). 1 model. Detailed comparisons with recent experimental data in the Pb region are amply discussed.

Nuclear binding energies: Global collective structure and local shell-model correlations

Nuclear Physics A, 2002

Shell Model Calculations for Nuclei with A=20

2012

Binding energy of the ground state, energy levels and the reduced probability for E2 transitions for O, F, Ne, Na and Mg nuclei with mass number A=20 and nucleon numbers between 8 and 12 have been calculated through shell model calculations using the shell model code OXBASH for Windows by employing the usdapn interaction for neutron and proton particles orbits in sd-shell. The binding energies calculations are in good agreement with experimental data. The predicted low-lying levels (energies, spins and parities) and the reduced probability for E2 transitions results are reasonably consistent with the available experimental data.

“Exact” shell model calculations in A = 17 and A = 18 nuclei and effective operators in the (2s, 1d) shell

Nuclear Physics A, 1974

A shell model calculation in an enlarged space spanned by two particles in the (2s, ld) shell and three-particle-one-hole 2h~o excitations is performed using the "bare" G-matrix. An effective interaction for the (2s, ld) shell is generated and its convergence properties are investigated. It is maintained that the series converges reasonably fast in G and that the singleparticle energies used in the calculation are instrumental in this respect. This conclusion is corroborated by the E2 effective charges and B(E2) strengths that we compute for A = 17 and A = 18 nuclei respectively. * See ref. 2) for a complete list of references. 171

Shell-model Monte Carlo studies of neutron-rich nuclei in the 1s-0d-1p-0f shells

Physical Review C, 1999

We demonstrate the feasibility of realistic Shell-Model Monte Carlo (SMMC) calculations spanning multiple major shells, using a realistic interaction whose bad saturation and shell properties have been corrected by a newly developed general prescription. Particular attention is paid to the approximate restoration of translational invariance. The model space consists of the full sd-pf shells. We include in the study some well-known T =0 nuclei and several unstable neutron-rich ones around N = 20, 28. The results indicate that SMMC can reproduce binding energies, B(E2) transitions, and other observables with an interaction that is practically parameter free. Some interesting insight is gained on the nature of deep correlations. The validity of previous studies is confirmed.

Tests and predictions of new effective interactions in the 0f1p shell

Nuclear Physics A, 1994

New two-body interactions were derived recently for nuclei in the lower part of the 0flp shell (A = 41-49) by fitting a semi-empirical potential form, known as a modified surface one-boson exchange potential (MSOBEP), and also two-body matrix elements, to 61 binding energy data. The wave functions based on these interactions are now used to calculate spectroscopic factors, B(E2) and B(MI) transition rates, and Gamow-Teller strengths in the full 0flp model space. Comprehensive comparisons with available experimental data are made to assess the quality of the wave functions. Good agreement between experiment and the calculated observables is generally found, which indicates that the new interactions are reliable approximations to the effective interaction in the 0flp shell.

Full 0homega shell model calculation of the binding energies of the 1f7/2 nuclei (original) (raw)

Related papers