Deformation-driven p-wave Halos at the Drip-line: 31Ne

The halo structure of Ne31 is studied using 1n-removal reactions on C and Pb targets at 230  MeV/nucleon. A combined analysis of the cross sections of these nuclear and Coulomb dominated reactions that feed directly the Ne30 ground-state reveals Ne31 to have a small neutron separation energy, 0.15+0.16−0.10  MeV, and spin-parity 3/2−. Consistency of the data with reaction and large-scale shell-model calculations identifies Ne31 as deformed and having a significant p-wave halo component, suggesting that halos are more frequent occurrences at the neutron drip line.