  Momentum distribution of fragments produced in 12C+12C reaction at 28.7
MeV/nucleon is analyzed with antisymmetrized version of molecular dynamics
(AMD). Calculations are made for several cases of stochastic collisions and the
projectile fragmentation peak in momentum distribution is reproduced by the
incorporation of many-body nature in stochastic collision process. Furthermore
the value of the cross section is found to be reflected in the low momentum
part of fragments such as alpha particles and 9Be.
