α-cluster structure of ¹⁸Ne

In this paper, we study α clustering in ¹⁸Ne and compare it with what is known about clustering in the mirror nucleus 18 O . The excitation function for ¹⁴O + α resonant elastic scattering was measured in inverse kinematics using the Texas active target detector system (TexAT). The data cover the excitation-energy range from 8 to 17 MeV. The analysis was performed using a multichannel R -matrix approach. The detailed spectroscopic information is obtained from the R -matrix analysis: excitation energy of the states, spin, and parity as well as partial α and total widths. This information is compared with theoretical models and previous data. Correspondence between the levels in ¹⁸O and ¹⁸Ne is established. We carried out an extensive shell-model analysis of the ¹⁸O and ¹⁸Ne mirror pair. The agreement between theory and experiment is very good and especially useful when it comes to understanding the clustering strength distribution. The comparison of the experimental data with theory shows that certain states especially at high excitation energies are significantly more clustered than predicted. This indicates that the structure of these states is collective and is aligned towards the corresponding α reaction channel.