Possibilities and limits of experimental results in the investigation of reaction dynamics in heavy ion reactions

The theoretical results of the individual xn, αxn, pxn, pαxn, and 2αxn evaporation residue excitation functions in the 16O+204Pb, 40Ar+180Hf, 82Se+138Ba, and 124Sn+92Zr reactions leading to the 220Th compound nucleus are presented and analyzed with the aim to study the entrance channel effects on the evaporation residue yields. The comparison of the complete theoretical results with the available experimental determinations shows a large difference connected with the unknown and unidentified nuclei of the total ER production. Such a difference between experimental and theoretical results also appears clearly by comparing the trend of the αERxn=αERtot ratio as a function of the excitation energy of the compound nucleus for the investigated reactions.