First observation of α-cluster states in the ¹⁴O + ⁴He interaction

We measured ¹⁴O+⁴He excitation functions for elastic scattering which demonstrate, for the first time, a well developed α-cluster structure in the proton rich nucleus, ¹⁸Ne. We present the excitation energies and estimates of the spins for the dominant resonances using an R-matrix approach. A resonance at 9.2 MeV excitation energy in ¹⁸Ne is particularly interesting. The spin-parity of the state is found to be 3^- and the α particle reduced width for the state appears to be comparable to the single particle limit. We have found indications for unusually large size of the observed α-cluster configuration.