P-Wave Nuclear Halos in ⁸B and ¹¹Be

We use a procedure to extract valuable information regarding the p-wave halos in ⁸B and ¹¹Be from the measured nuclear asymptotic normalization coefficients. With this procedure, we evaluate the probabilities of valence particle being outside the binding potential, which are 0.31±0.03 for the ⁸B ground state and 0.59±0.06 for the ¹¹Be first excited state. More than 50% probability outside the binding potential means that the ¹¹Be first excited state has a typical p-wave neutron halo. The rms radii are obtained to be 3.9±0.2 fm for the valence proton in the ⁸B ground state and to be 6.5±0.3 fm for the valence neutron in the ¹¹Be first excited state. The probabilities of the valence particle being in the non-classical region are extracted to be 0.41±0.04 and 0.46±0.05 for the ⁸B ground state and the ¹¹Be first excited state, respectively. The results demonstrate that although hindered by the effects of Coulomb and/or centrifugal barriers, their valence particle wavefunction still penetrates substantially into the classically forbidden region.