$\alpha$-Clustering in $^{18}$O

The $\alpha$-cluster structure of $N\neq Z$ nuclei is poorly known and is a subject of intense theoretical discussion. $\alpha$-clusters have been used to explain various nuclear effects including quasi-rotational bands of states with large $\alpha$-particle widths, which were observed in light 4N nuclei, $^{8}$Be, $^{12}$C, $^{16}$O and $^{20}$Ne. We report on the observation of the $\alpha$-cluster structure in the $N\neq Z$ nucleus $^{18}$O. The $\alpha$-cluster structure of $^{18}$O was studied through $\alpha+^{14}$C elastic scattering using the Thick Target Inverse Kinematics (TTIK) technique. The analysis was performed using a multi-level, multi-channel \textbf{R}-Matrix approach. It was found that $^{18}$O has an elaborate $\alpha$-cluster structure, including two unusual states with $\alpha$ widths exceeding the formal single particle limit. A comparison of the observed $^{18}$O $\alpha$-cluster structure with the predictions of potential model approach was performed. A more detailed description of the two very broad states can be given using this potential model approach.