15O+α resonant elastic scattering to study cluster states in19Ne

Clustering phenomena are well known in nuclear physics for stable nuclei, both α-conjugate (N=Z, A=2N), like8Be,16O,20Ne, and non-α-conjugate, like6Li and7Li. In general, it is expected that light exotic nuclei may also exhibit cluster behavior. Moving out of the valley of stability configurations can be found where at least one of the clusters is unbound or weakly bound, thus not satisfying the strong internal correlation requirement of classical clusters. This is so-called exotic clustering. The study of such systems presents many difficulties, due, mainly, to the low intensities typical of radioactive ion beams. Therefore, few significant experimental studies have been performed so far. In this work we searched for α-cluster states in19Ne above its α-decay threshold measuring, for the first time, the15O(4He,4He) elastic scattering excitation function. Moreover, this study classified low-energy states in Ne in the astrophysically important region in this HCNO-break-out nucleus.