Extreme α-clustering in the 18O nucleus

Abstract

The structure of the 18O nucleus at excitation energies above the α decay threshold was studied using 14C + α resonance elastic scattering. A number of states with large α reduced widths have been observed, indicating that the α-cluster degree of freedom plays an important role in this N ≠ Z nucleus. A 0+ state with an α reduced width exceeding the single-particle limit was identified at an excitation energy of 9.9 ± 0.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature. © Società Italiana di Fisica / Springer-Verlag 2009.