Interpretation of Coulomb breakup of 31Ne in terms of deformation

The recent experimental data on Coulomb breakup of the nucleus Ne-31 are interpreted in terms of deformation. The measured large one-neutron removal cross section indicates that the ground state of Ne-31 is either an s halo or a p halo. The data can be most easily interpreted as the spin of the ground state being 3/2(-) coming from either the Nilsson level [330 1/2] or the Nilsson level [321 3/2] depending on the neutron separation energy S-n. However, the possibility of 1/2(+) coming from [200 1/2] is not excluded. It is suggested that if the large ambiguity in the measured value of S-n of Ne-31, 0.29 +/- 1.64 MeV, can be reduced by an order of magnitude, say to be +/- 100 keV, one may get a clear picture of the spin-parity of the halo ground state.