MULTIPLICITY OF CHARGED PARTICLES IN PB - PB COLLISIONS AT SPS ENERGIES

Antinori, F.; Bacon, P.; Badala, A.; Barbera, R.; Belogianni, A.; Bhasin, A.; Bloodworth, I. J.; Bombara, M.; Bruno, G. E.; Bull, S. A.; Caliandro, R.; Campbell, M.; Carena, W.; Carrer, N.; Clarke, R. F.; Dainese, A.; DE HAAS, A. P.; DE RIJKE, P. C.; DI BARI, D.; DI LIBERTO, S.; Divia, R.; Elia, D.; Evans, D.; Feofilov, G. A.; Fini, R. A.; Ganoti, P.; Ghidini, B.; Grella, G.; Helstrup, H.; Hetland, K. F.; Holme, A. K.; Jacholkowski, A.; Jones, G. T.; Jovanovic, P.; Jusko, A.; Kamermans, R.; Kinson, J. B.; Knudson, K.; Kolozhvari, A. A.; Kondratiev, V.; Kralik, I.; Kravcakova, A.; Kuijer, P.; Lenti, V.; Lietava, R.; Lovhoiden, G.; Manzari, V.; Martinska, G.; Mazzoni, M. A.; Meddi, F.; Michalon, A.; Morando, Maurizio; Nappi, E.; Navach, F.; Norman, P. I.; Palmeri, A.; Pappalardo, G. S.; Pastircak, B.; Pisut, J.; Pisutova, N.; Platt, R. J.; Posa, F.; Quercigh, E.; Riggi, F.; Rohrich, D.; Romano, G.; Safark, K.; Sandor, L.; Schillings, E.; Segato, Gianfranco; Sene, M.; Sene, R.; Snoeys, W.; Soramel, Francesca; SPYROPOULOU STASSINAKI, M.; Staroba, P.; Toulina, T. A.; Turrisi, R.; Tveter, T. S.; Urban, J.; Valiev, F. F.; VAN DEN BRINK, A.; VAN DE VEN, P.; VANDE VYVRE, P.; VAN EIJNDHOVEN, N.; VAN HUNEN, J.; Vascotto, A.; Vik, T.; VILLALOBOS BAILLIE, O.; Vinogradov, L.; Virgili, T.; Votruba, M. F.; Vrlakova, J.; Zavada, P.

doi:10.1088/0945-3899/31/5/004

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/c and 40 A GeV/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 increase is compatible with a logarithmic dependence on the centre of mass energy. The results are compared with those from other experiments and with the VENUS and RQMD models.