Examination of evidence for resonances at high excitation energy in the 7α disassembly of Si28

The experimental excitation function for the $7\ensuremath{\alpha}$ de-excitation of $^{28}\mathrm{Si}$ nuclei excited to high excitation energies in the collisions of 35 MeV/nucleon $^{28}\mathrm{Si}$ with $^{12}\mathrm{C}$ reveals resonance structures. The possibility that these structures may indicate the population of toroidal high-spin isomers such as those predicted by a number of recent theoretical calculations is discussed and the need for further investigations is emphasized.