Nuclear shape deformations in 485-MeV56Fe+197Au reactions

Detailed coincidence studies of light-charged-particle evaporation in 485-MeV ${}_{}{}^{56}{}_{}{}^{}\mathrm{Au}$ reactions have recently been used to probe the features of fusion-like fission and deeply inelastic reaction mechanisms. We summarize here the average statistical properties which characterize the several identified groups of hot nuclear emitters. These properties are derived from comparisons of observed ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ ${/}^1$H energy spectra and angular distributions with model calculations. The results demonstrate remarkably low effective evaporation barriers for the very heavy composite system produced here, consistent with the trends found previously for much lighter systems.