Mass spectrometer measurements of the neutron rich sodium isotopes show a sudden increase at 31Na in the values of the two-neutron separation energies. The spherical shell model naturally predicts a sudden decrease at 32Na after the N = 20 shell closure. We propose that the explanation for this disagreement lies in the fact that sodium isotopes in this mass region are strongly deformed due to the filling of negative parity orbitais from the 1f 7 2 shell. Hartree-Fock calculations are presented in support of this conjecture.
ASJC Scopus subject areas
- Nuclear and High Energy Physics