Interpretation of Coulomb breakup ofNe31in terms of deformation

Abstract

The recent experimental data on Coulomb breakup of the nucleus $^{31}\mathrm{Ne}$ are interpreted in terms of deformation. The measured large one-neutron removal cross section indicates that the ground state of $^{31}\mathrm{Ne}$ 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/${2}^{\ensuremath{-}}$ 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 $^{31}\mathrm{Ne}$, $0.29\ifmmode\pm\else\textpm\fi{}1.64$ MeV, can be reduced by an order of magnitude, say to be $\ifmmode\pm\else\textpm\fi{}100$ keV, one may get a clear picture of the spin-parity of the halo ground state.