  Collective transverse momentum flow of nucleons and fragments in intermediate
energy 40Ar + 27Al collisions is calculated with the antisymmetrized molecular
dynamics (AMD). The observed flow and its balance energy are reproduced very
well by the calculation with the Gogny force which corresponds to the soft EOS
of the nuclear matter. Especially the calculated absolute value of the fragment
flow is larger than that of the nucleon flow in the negative flow region, which
can be explained by the existence of two components of flow. In addition to
many similarities, difference in the deuteron flow is found between 12C + 12C
and 40Ar + 27Al collisions, and its origin is investigated by paying attention
to the production mechanism of light fragments. We also investigate the
dependence of the flow of nucleons and fragments on the stochastic collision
cross section and the effective interaction, and conclude that the stiff EOS
without momentum dependence of the mean field is not consistent to the
experimental data.
