  Statistical properties of the antisymmetrized molecular dynamics (AMD) are
classical in the case of nucleon emission processes, while they are quantum
mechanical for the processes without nucleon emission. We first clarify that
there coexist mutually opposite two statistics in the AMD framework: One is the
classical statistics of the motion of wave packet centroids and the other is
the quantum statistics of the motion of wave packets which is described by the
AMD wave function. We prove the classical statistics of wave packet centroids
by using the framework of the microcanonical ensemble of the nuclear system. We
show that the quantum statistics of wave packets emerges from the classical
statistics of wave packet centroids. It is emphasized that the temperature of
the classical statistics of wave packet centroids is different from the
temperature of the quantum statistics of wave packets. We then explain that the
statistical properties of AMD for nucleon emission processes are classical
because nucleon emission processes in AMD are described by the motion of wave
packet centroids. When we improve the description of the nucleon emission
process so as to take into account the momentum fluctuation due to the wave
packet spread, the AMD statistical properties for nucleon emission processes
change drastically into quantum statistics. Our study of nucleon emission
processes can be conversely regarded as giving another kind of proof of the
fact that the statistics of wave packets is quantum mechanical while that of
wave packet centroids is classical.
