Angular momentum projected analysis of quadrupole collectivity in 30,32,34Mg and 32,34,36,38Si With the Gogny interaction

A microscopic angular momentum projection after variation is used to describe quadrupole collectivity in Mg-30,Mg-32,Mg-34 and Si-32,Si-34,Si-36,Si-38. The Hartree-Fock-Bogoliubov states obtained in the quadrupole constrained mean field approach are taken as intrinsic states for the projection. Excitation energies of the first 2(+) states and the B(E2,0(+)-->2(+)) transition probabilities are given. A reasonable agreement with available experimental data is obtained. It is also shown that the mean field picture of those nuclei is strongly modified by the projection. (C) 2000 Published by Elsevier Science B.V. All rights reserved.