Pseudorapidity distribution of charged particles from pp Au+Au collisions at RHIC energies Original Research Article

Charged-particle multiplicities as a function of pseudorapidity and collision centrality for Au+Au collisions at √SNN = 130 GeV are presented. For the 5% most central events, dNch/dη|η=0 and Nch|−4.7<η<4.7 are found to increase by 14% and 21% from the lower to higher energy, respectively. In addition, dNch/dη results for pp collisions at √SNN = 200 GeV are presented. A significant increase is found for the charged-particle production per participant nucleon pairs in going from pp to the most central Au+Au collisions.