The Halo of 14Be
  The two-neutron halo nucleus 14Be has been investigated in a kinematically complete measurement of the fragments (12Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross-sections, neutron angular distributions and invariant mass spectra characteristic of a halo were observed and the electromagnetic (EMD) contributions deduced. Comparison with three-body model predictions indicate that the halo wavefunction contains a large 2s1/2^2 admixture. The EMD invariant mass spectrum exhibited a relatively narrow structure near threshold (Edecay=1.8+/-0.1 MeV, Gamma = 0.8+/-0.4 MeV) consistent with a soft-dipole excitation. 
M. Labiche, N.A. Orr, F.M. Marques, J.C. Angelique, L. Axelsson, B.   Benoit, U.C. Bergmann, M.J.G. Borge, W.N. Catford, S.P...