Multipole deformations, static quadrupole moments and electromagnetic transitions in light nuclei

Abstract

Hartree-Fock calculations have been performed in light 4 n nuclei from 8Be to 28Si using central interactions. The rms radii, static quadrupole moments and electromagnetic transition rates have been deduced exactly from the angular momentum projected wave functions obtained in a projection before variation (PBV) procedure. The quadrupole and hexadecapole deformations of the intrinsic states are compared with the experimental results deduced recently from the analysis of electron, proton and α-particle inelastic scattering data. The whole system of A nucleons is treated and consequently we do not introduce any additional effective charge. A detailed comparison with experiment is made and good agreement is obtained, with some exceptions in 12C and 28Si. Our projected HF description is compared with other microscopic investigations of light nuclei and with the phenomenological rotational-model predictions. The importance of the PBV procedure is displayed and remarks are also made concerning the usual approximations used to deduce the nuclear properties from the HF wave functions.