Gluon shadowing and hadron production at RHIC

Hadron multiplicity in the central rapidity region of high-energy heavy-ion collisions is investigated within a two-component mini-jet model which consists of soft and semi-hard particle production. The hard contribution from mini-jets is reevaluated using the latest parameterization of parton distributions and nuclear shadowing. The energy dependence of the experimental data from RHIC requires a strong nuclear shadowing of the gluon distribution in this model. The centrality dependence of the hadron multiplicity at roots = 130 GeV is reproduced well with the impact-parameter dependent parton shadowing. However, energy variation of the centrality dependence is needed to distinguish different particle production mechanisms such as the parton saturation model. (C) 2002 Elsevier Science B.V. All rights reserved.