Effect of clustering on the emission of light charged particles

Energy spectra of light charged particles emitted in the reaction p + ²⁷Al → ²⁸Si* have been studied and compared with statistical model calculation. Unlike ¹⁶O + ¹²C where a large deformation was observed in ²⁸Si*, the energy spectra of α-particles were well explained by the statistical model calculation with standard ''deformability parameters'' obtained using the rotating liquid drop model. It seems that the α-clustering in the entrance channel causes extra deformation in ²⁸Si* in the case of ¹⁶O + ¹²C, but the reanalysis of other published data shows that there are several cases where extra deformation was observed for composites produced via non-α-cluster entrance channels also. An empirical relation was found between mass-asymmetry in the entrance channel and deformation, which indicates that along with α-clustering, mass-asymmetry may also affect the emission of a light charged particle. (orig.)