Light-charged-particle evaporation from hot $\chem{^{31}P}$ nucleus at $\mth{E^{*} \sim 60}$ MeV

The inclusive energy spectra of light charged particles, such as, $\alpha$, p, d and t, evaporated from the hot $\chem{^{31}P}$ nucleus at an excitation energy $E^{*} \sim 60$ MeV, have been measured at various angles. The compound nucleus $\chem{^{31}P}$ has been populated using two different entrance channel configurations; i.e., $\chem{^{7}Li}$ (47 MeV) + $\chem{^{24}Mg}$ and $\chem{^{19}F}$ (96 MeV) + $\chem{^{12}C}$ reactions, leading to the same excitation energy of the compound system. It has been observed that the spectra obtained in the $\chem{^{7}Li}$ (47 MeV) + $\chem{^{24}Mg}$ reaction follow the standard statistical-model prediction with a spherical configuration of the compound nucleus. But, the spectra obtained in the $\chem{^{19}F}$ (96 MeV) + $\chem{^{12}C}$ reaction deviate from similar predictions of the statistical model both on higher- as well as on lower-energy sides. Considerable deformation was required to be incorporated in the calculation in order to reproduce the measured-energy spectra in this case. Dynamical trajectory model calculations were not found to play any significant role in explaining the differences in behaviour between the two cases under study. The observed discrepancy has been attributed to the difference in the angular-momentum distributions of the compound nuclei formed in the two reactions