Comparison of techniques for computing shell-model effective operators

Abstract

Different techniques for calculating effective operators within the framework of the shell model using the same effective interaction and the same excitation spaces are presented. Starting with the large-basis no-core approach, we compare the time-honored perturbation-expansion approach and a model-space truncation approach. Results for the electric quadrupole and magnetic dipole operators are presented for ${}^6$Li. The convergence trends and dependence of the effective operators on differing excitation spaces and Pauli Q-operators is studied. In addition, the dependence of the electric-quadrupole effective charge on the harmonic-oscillator frequency and the mass number, for A=5,6, is investigated in the model-space truncation approach.

18 pages. REVTEX. 4 PostScript figures

References in corpus (5)

• Construction of high-quality Nucleon-Nucleon potential models
• No-core shell-model calculations with starting- energy-independent multi-valued effective interactions
• Large-basis shell model studies of light nuclei with a multi-valued G-matrix effective interaction
• E2 properties of nuclei far from stability and the proton-halo problem of 8B
• Comparison of the Effective Interaction to Various Orders in Different Mass Regions

Cited by in corpus (1)

• Ab initio electromagnetic observables with the in-medium similarity renormalization group