UAM, Madrid

Influence of the constraining in quadratic operators on calculations beyond the mean field in Magnesium isotopes

We have performed angular momentum projection calculations in constrained Hartree-Fock-Bogoliubov wave functions of even-even Magnesium nuclei with the Gogny force. The mean field calculations were constrained to fixed values of the quadrupole deformation and its fluctuations . This procedure allows the study of the dynamics of the quadrupole deformation, the achievement of more accurate spectra after the projection and the calculation of the energy at low deformation and angular momentum not equal to zero. Furthermore, we have study the collective motion in the framework of Generator Coordinate Method with the quadrupole deformation as generator coordinate. For GCM calculations we have used the wave functions were the quadrupole fluctuations give the lower energy. The comparison of the above calculations and the results of the projection without introducing the fluctuation freedom degree gives negligible differences which points out the \"rigidity\" of the eve-even Magnesium nuclei.