Counting the number of degrees of freedom in hot nucleus-nucleus systems from the preequilibrium emission of nucleons

In a previous study, the authors showed that the emission models used in the analysis of preequilibrium particles from light-ion reactions could be successfully applied, with appropriate modification, to the analysis of particles emitted from a nucleus-nucleus collision in an early stage of the reaction process. For that purpose, they used (a) the first term of the Griffin exciton model expansion and the Harp-Miller-Berne equilibration model in a modified form. Having established the feasibility of such analysis, the authors concentrate on its physical information content, and discuss in particular the significance of the relevant parameters that enter in the analysis, namely the initial number of degrees of freedom that share the available energy and the total time of preequilibrium emission