  The dynamics of partons, hadrons and strings in relativistic nucleus-nucleus
collisions is analyzed within the novel Parton-Hadron-String Dynamics (PHSD)
transport approach, which is applied to Pb+Pb collisions from 20 to 160 A GeV
in order to explore the space-time regions of 'partonic matter'. We find that
even central collisions at the top-SPS energy of 158 A GeV show a large
fraction of non-partonic, i.e. hadronic or string-like matter, which can be
viewed as a hadronic corona. Furthermore, we observe that the partonic phase
has a very low impact on rapidity distributions of hadrons but a sizeable
influence on the transverse mass distribution of final kaons due to the
repulsive partonic mean fields. We also find a significant effect on the
production of multi-strange antibaryons due to a slightly enhanced $s{\bar s}$
pair production in the partonic phase from massive time-like gluon decay and a
larger formation of antibaryons in the hadronization process. All differential
hadron spectra are analyzed in comparison to the data of experimental
collaborations.
