Baryon Stopping and Charged Particle Distributions in Central Pb+Pb Collisions at 158 GeV per Nucleon

Net proton and negative hadron spectra for central Pb+Pb collisions at 158 GeV per nucleon at the CERN SPS were measured and compared to spectra from lighter systems. Net baryon distributions were derived from those of net protons. Stopping and mean transverse momentum <pT> of net baryons increase with system size. The rapidity density of negative hadrons scales with the number of participant nucleons for nuclear collisions, whereas their <pT> is independent of system size. The <pT> systematics are consistent with larger transverse flow velocity at midrapidity for Pb+Pb compared to S+S central collisions.