Branching ratio and information entropy for the p+${}^{12}$C reaction in the extended-quantum-molecular-dynamics model

The reactions of p+${}^{12}$C with triangular 3$\alpha$ structure and spherical structure with incident energies ranging from 5 to 200 MeV/nucleon are simulated by the in the extended-quantum-molecular-dynamics (EQMD) model together with the GEMINI decay process. This paper presents the incident energy dependence of the branching ratios of fragment production and multiplicity, as well as the associated event information entropy. The results indicate that the triangular 3$\alpha$ ${}^{12}$C has an extra branching ratio for the quasi-elastic reaction compared to the spherical ${}^{12}$C. This peculiarity of the branching ratios of the triangular 3$\alpha$ ${}^{12}$C appears as a small dent in the curves of the event information entropy (both the fragment information entropy and the multiplicity information entropy). Therefore, we propose that the event information entropy could be a probe for detecting the $\alpha$-cluster structure.