Interpretation of Coulomb breakup of 31Ne in terms of deformation

Abstract

The recent experimental data on Coulomb breakup of the nucleus ${}^{31}$Ne are interpreted in terms of deformation. The measured large one-neutron removal cross-section indicates that the ground state of ${}^{31}$Ne is either s- or 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 [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 ${}^{31}$Ne, 0.29$\pm 1.64$ MeV, can be reduced by an order of magnitude, say to be $\pm$100 keV, one may get a clear picture of the spin-parity of the halo ground state.

Comments: 8 pages, 4 figures