Structure in ²⁸Si(¹⁶O, ¹²C)³²S excitation functions

Oscillatory structure appears in ²⁸Si(¹⁶O, ¹²C) excitation functions populating the ground state and first excited state of ³²S over a range of center-of-mass bombarding energy from 22.3 MeV to 32.5 MeV. This structure is weaker in magnitude and less regular than that previously reported for ²⁴Mg(¹⁶O, ¹²C) excitation functions. The structure in the ²⁸Si → ³²S ground state excitation function does not correlate with entrance or exit channel elastic scattering excitation functions, but it does correlate with some of the structure observed in excitation functions for ²⁸Si(¹⁶O, ¹⁶O)²⁸Si^*(2⁺). At most bombarding energies the ²⁸Si → ³²S ground state transition shows angular distributions which are dominated by one grazing partial wave (which can be calculated with the sample semiclassical Frahn-Venter model), but in two narrow energy ranges the angular distributions shift abruptly to oscillatory shapes which are not dominated by the grazing partial wave.