Intermediate mass fragment emission as a probe of nuclear dynamics

Element distributions and fragment multiplicity distributions have been measured for E/A=50 MeV ${}_{}{}^{129}{}_{}{}^{}\mathrm{Xe}$ ${+}^{12}$C, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$, ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$, and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ reactions using a low threshold 4π detector. Both distributions show a strong correlation with the detected charged particle multiplicity and a large degree of target independence. The measured distributions are compared with hybrid model calculations which incorporate important dynamical aspects in both the preequilibrium and statistical emission phases. Results of these calculations are in reasonable agreement with the data. However, uncertainties with regard to the compressibility of nuclear matter remain due to uncertainties in the coupling of the two models.