Energy Dependence of Proton-Induced Xenon Fragmentation and the Approach to Liquid-Gas Criticality in Nuclear Matter

Cross sections ascribed to a multifragmentation process have been obtained from the measured fragment yields ($3\ensuremath{\le}{Z}_{f}\ensuremath{\le}14$) in proton-xenon interactions ($1\ensuremath{\le}{E}_{p}\ensuremath{\le}20$ GeV). The variation of the yields with both mass and bombarding energy can be understood by use of the droplet model of the liquid-gas phase transition. With increasing energy, this model indicates that multifragmentation occurs first in the mechanical-instability region, next in the supersaturated vapor, and finally in the critical region.