Comparison between models of the decay of light compound nuclei

Abstract

The decay of the compound nucleus is traditionally calculated using one of two types of statistical models, either a sequential or a simultaneous emission one. The best known sequential emission models are the Weisskopf-Ewing one and the Hauser-Feshbach one. Both sequential emission models emit only one particle at a time. A well know simultaneous emission model is the Fermi breakup one, which takes into account the fragmentation of the compound nuclei into two, three or more residual nuclei/particles. We have compared the particle and residual nucleus distributions of the Weisskopf-Ewing and Fermi breakup models in the case in which only stable nuclei/particles are emitted. We find that the Weisskopf-Ewing results in larger yields of light particles and heavy residues than the Fermi breakup model, while the latter results in larger yields of intermediate mass fragments.