Molecular orbital theory for intermediate structure in the excitation function of heavy-ion reactions

In the excitation function for the elastic scattering between an α-conjugate target and projectile, there often exist intermediate structures which cannot be interpreted easily either by conventional optical potential model or statistical theory. A nuclear molecular-orbital approximation theory for the α-transfer mechanism has been formulated and applied to the 24Mg(16O,12C)28Si reaction. The excitation function at θc.m. = 00 and differential cross section in the whole angle region at three different energies Ec.m. = 27.8, 30.8 and 36.2 MeV are calculated. The calculations reproduce well these experimental curves with a common set of parameters. The intermediate structures shown naturally in the excitation function and the anomalous oscillatory structures appear in the whole angle region of the differential cross section. (orig.)