Thermodynamics — a valuable approach to multifragmentation? Original Research Article

Since years it has been vividly debated whether multifragmentation is a thermal or a dynamical process. Recently it has been claimed in two publications that new data allow to decide this question. The conclusion, drawn in these papers, are, however, opposite. Whereas in one of them it is stated that the behavior of different observables as a function of the fragment multiplicity excludes a thermal origin of the fragments, in the other it is argued that data show a first-order phase transition between a liquid and a gaseous phase. It is the aim of this paper to show that both conclusions are premature. They are based on the salient assumption, that the system is sufficiently large to be susceptible to a canonical description. We will show that this is not the case. A micro canonical approach describes the data as good as dynamical calculations. Hence the quest for the physical origin of multifragmentation continues.