Dynamics of the Multifragmentation of 1 A GeV Gold on Carbon

An exclusive study of the interaction of 1{ital A}GeV Au with C shows a separability into two stages: a prompt stage involving emission of most {ital Z}=1 and some {ital Z}=2 particles and a second stage involving the decay of an equilibrated remnant, which typically undergoes multifragmentation. The mean mass, charge, excitation energy, and the initial temperature {ital T}{sub {ital i}} of the remnant have been determined as a function of the total charge multiplicity, {ital m}, as has the freeze-out temperature {ital T}{sub {ital f}}. Both {ital T}{sub {ital i}} and {ital T}{sub {ital f}} increase linearly with {ital m} and their values at the critical point have been determined. {ital T}{sub {ital f}} rises monotonically with excitation energy as expected for a continuous phase transition. {copyright} {ital 1996 The American Physical Society.}