Pseudorapidity distributions of charged particles from Au+Au collisions at the maximum RHIC energy, root s(NN)=200 GeV

Abstract

We present charged-particle multiplicities as a function of pseudorapidity and collision centrality for the Au-197+ Au-197 reaction at roots(NN)=200 GeV . For the 5% most central events we obtain dN(ch)/detaparallel to(eta=0) =625+/-55 and N(ch)parallel to(-4.7less than or equal toetaless than or equal to4.7) =4630+/-370, i.e., 14% and 21% increases, respectively, relative to roots(NN)=130 GeV collisions. Charged-particle production per pair of participant nucleons is found to increase from peripheral to central collisions around midrapidity. These results constrain current models of particle production at the highest RHIC energy.