  The charge density distribution with respect to the velocity of matter
produced in peripheral heavy ion reactions around Fermi energy is investigated.
The experimental finding of enhancement of mid-rapidity matter shows the
necessity to include correlations beyond BUU which was performed in the
framework of nonlocal kinetic theory. Different theoretical improvements are
discussed. While the in-medium cross section changes the number of collisions,
it leaves the transferred energy almost unchanged. In contrast the nonlocal
scenario changes the energy transferred during collisions and leads to an
enhancement of mid-rapidity matter. The renormalisation of quasiparticle
energies can be included in nonlocal scenarios and leads to a further
enhancement of mid-rapidity matter distribution. This renormalisation is
accompanied by a dynamical softening of the equation of state seen in longer
oscillation periods of the excited compressional collective mode. We propose to
include quasiparticle renormalisation by using the Pauli-rejected collisions
which circumvent the problem of backflows in Landau theory. Using the maximum
relative velocity of projectile and target like fragments we associate
experimental events with impact parameters of the simulations. For peripheral
collisions we find a reasonable agreement between experiment and theory. For
more central collisions, the velocity damping is higher in one-body simulations
than observed experimentally, because of missing cluster formations in the
kinetic theory used.
