MODERN PHYSICS LETTERS A, cilt.32, sa.9, 2017 (SCI-Expanded)
The elastic scattering data of alpha+O-16 and alpha+Ca-40 systems at E-lab = 32.2-146 MeV and E-lab = 24.1-49.5 MeV energies have been analyzed with double-folding (DF) potential in optical model formalism in order to investigate the cluster structures of Ne-20 and Ti-44 nuclei. The deduced DF potentials between alpha and O-16 as well as alpha and Ca-40 have been used for obtaining the excitation energies and alpha-decay widths of Ne-20 and Ti-44 in Gamow code, but the reasonable results could not be obtained. Thus, the real parts of DF potentials which are in the best agreement with experimental data have been fitted with the squared-Woods-Saxon (WS2) potential parameters to calculate the alpha-decay widths of Ne-20 and Ti-44 with Wentzel-Kramers-Brillouin (WKB) approach. The nuclear potential sets obtained in WKB calculations are also used for Gamow code calculations. We take into account the deformation and orientation of Ca-40 nucleus to examine their influence on both the excitation energies and decay widths of Ti-44. Besides, by using the binary cluster model the rotational band energies and electromagnetic transition probabilities (BE2)s according to angles are also reproduced for both nuclei. The obtained results showed that the binary cluster model is very useful to understand the observables of Ne-20 and Ti-44 nuclei. Although only spherical calculations are made for Ne-20 (alpha + O-16), the deformation in Ca-40 would be important for the understanding of Ti-44 (alpha + Ca-40) cluster structure. The mechanism presented here would also be applied to understand the cluster structures in heavy nuclei.