Centrality Dependence of Charged Particle Multiplicity in Au-Au   Collisions at sqrt(s_NN)=130 GeV
  We present results for the charged-particle multiplicity distribution at mid-rapidity in Au - Au collisions at sqrt(s_NN)=130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find $dN_{ch}/d\eta_{|\eta=0} = 622 \pm 1 (stat) \pm 41 (syst)$. The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality. 
PHENIX Collaboration: K. Adcox, et al