Deformation of nuclei close to the two-neutron drip line in the Mg region

J. Terasaki (1) , H. Flocard (1) , P-H. Heenen , P. Bonche (2)

1 IPNO - Institut de Physique Nucléaire d'Orsay
2 SPhT - Service de Physique Théorique

We present Hartree-Fock-Bogoliubov (HFB) calculations of the ground states of even Mg isotopes. A Skyrme force is used in the mean-field channel and a density-dependent zero-range force in the pairing channel. $^{40}$Mg and $^{20}$Mg are predicted to be at the two-neutron and two-proton drip lines respectively. A detailed study of the quadrupole deformation properties of all the isotopes shows that the ground states of $^{36,38,40}$Mg are strongly deformed with significantly different deformations for the neutrons and protons. Our study supports the disappearance of the $N$ = 28 shell gap in the Mg and Si isotopes.

Domaines: Physique Nucléaire Théorique [nucl-th]

J. Terasaki, H. Flocard, P-H. Heenen, P. Bonche. Deformation of nuclei close to the two-neutron drip line in the Mg region. Nuclear Physics A, 1997, 621, pp.706-718. ⟨10.1016/S0375-9474(97)00183-8⟩. ⟨in2p3-00000291⟩