## 4 Discussion and Conclusions  
In previous experiments, the description of the energy spectra of \(\alpha\)-particles and protons emitted from nuclei produced at large angular momenta required resorting to very large deformations for high spin compound nucleus states [11; 12] or required an ad hoc modification of the ingredients included in the SM, as for instance in [9; 37]. The charged particles emitted in the evaporation channel in light composite systems make them well suited for verification of the evaporation decay process description provided by the statistical model. These particles are (i) very sensitive to the nuclear shapes of emitting nuclei, and (ii) originate by a single decay process dominating at all angular momenta, i.e., it is in negligible competition with other processes, such as fission. Hence, they represent powerful probes to map nuclear shape evolution as a function of excitation energy and angular momentum. In this work, we reanalyzed the evaporative light charged particles emitted by the \({}^{67}\)Ga nuclei at E\({}_{\rm x}\) = 91 MeV by performing a comparative analysis of data and GANES simulations from the literature [12] with the results of the LILITA_N21 SM code. Energy spectra and the angular distributions and ratios of the double differential protons and \(\alpha\) particles were collected using the reaction \({}^{40}\)Ar + \({}^{27}\)Al at an incident laboratory energy of E\({}_{\rm lab}\) = 190 MeV. The \(\alpha\) particle and proton energy spectra had not previously been reproduced with the single-step Monte Carlo approach, and in order to reproduce a subset of these, a very large deformation was assumed. The comparative analysis performed in this work was aimed at reproducing the full set of observables by taking advantage of the features of the LILITA_N21 evaporative code [14] in order to make our conclusion as solid as possible as well as to impose stringent constraints on the parameters characterizing CN decay. The LILITA_N21 code, which includes new Optical Model transmission coefficients, along with the multi-step Monte Carlo approach of the SM and a nuclear shape description based on the nuclear stratosphere provided an escape route from the previous impasse. A satisfactory reproduction of the complete set of observables was thereby obtained. In our calculation, we used: (i) a nuclear level density parameter, \"a = A/8\"; (ii) spherical nuclei with and without a small stratosphere volume; and (iii) transmission coefficients based on Optical Model potential parameters recently derived from global fits [27; 28]. Concerning the OM parameterizations, it is worth noting that they include wide mass and energy ranges for emitting particles and a dependence on the difference between the neutron and proton \begin{table}
\begin{tabular}{c c c c} \hline \(\mathbf{\theta}\) & **Exp.[12]** & **LILITA-SS** & **LILITA-NS** \\ \hline \(10^{\circ}\) & 1.56 & 2.04 & 1.62 \\ \(45^{\circ}\) & 0.55 & 1.12 & 0.81 \\ \hline \end{tabular}
\end{table} 
Table 2: Double differential multiplicities ratio among \(\alpha\) particles and protons measured at most forward (\(\theta_{lab}=10^{\circ}\)) and most backward (\(\theta_{lab}=45^{\circ}\)) directions. The experimental data from the literature are compared with LILITA_N21 calculations using the SS and NS prescriptions. For more details, see the text. numbers that makes them well suited for calculations involving nuclei far from stability. Further improvements in SM ingredients, such as nuclear level density dependence on the isospin and nuclear temperature (as considered in [38]) and transmission coefficients, could be reached by simultaneously exploring evaporation residue yields and the neutron energy and angular distributions in the evaporative channels.