Multiplicity Fluctuations in Au+Au Collisions at RHIC

Understand

The preliminary data of the PHENIX collaboration for the scaled variances of charged hadron multiplicity fluctuations in Au+Au at $\sqrt{s}=200$ GeV are analyzed within the model of independent sources.

• We use the HSD transport model to calculate the participant number fluctuations and the number of charged hadrons per nucleon participant in different centrality bins.
• This combined picture leads to a good agreement with the PHENIX data and suggests that the measured multiplicity fluctuations result dominantly from participant number fluctuations.
• The role of centrality selection and acceptance is discussed separately.