# Multiplicity of charged particles in Pb-Pb collisions at SPS energies

Authors
Publication Date
Source
HAL-IN2P3
Keywords
• [Phys.Hexp] Physics [Physics]/High Energy Physics - Experiment [Hep-Ex]
The multiplicity of charged particles in the central rapidity region has been measured by the NA57 experiment in Pb--Pb collisions at the CERN SPS at two beam momenta: 158 A GeV/{\it c} and 40 A GeV/{\it c}. The value of $dN_{ch}/d\eta$ at the maximum has been determined and its behaviour as a function of centrality has been studied in the centrality range covered by NA57 (about 50% of the inelastic cross section). The multiplicity increases approximately logarithmically with the centre of mass energy.