Overview of hadronic observables measured by NA49 at the CERN/SPS in central $^{208}$Pb+Pb collisions at 158 GeV/nucleon

Results on single and two-particle distributions measured by NA49 experiment in central /sup 208/Pb+Pb collisions at 158 GeV/nucleon are presented. Their relevance concerning the observation and characterisation of an extended equilibrated deconfined state of partonic matter, the quark gluon plasma (QGP) is discussed. Available data support that sufficient energy density for a phase transition of normal hadronic matter to a deconfined state is reached at the early stage of such collisions. The evolution of the created system is probed via hadronic observables, and information on transverse expansion, chemical and thermal freeze-out is obtained. Comparisons of particle abundances for different collision systems and energies suggest that /sup 208/Pb+Pb collisions cannot be described as a superposition of independent elementary collisions. (18 refs).