Importance of reaction volume in hadronic collisions: Canonical enhancement

We study the canonical flavor enhancement arising from exact conservation of strangeness, and charm flavor. Both the theoretical motivation, and the practical consequences are explored. We argue using qualitative theoretical arguments and quantitative evaluation, that this proposal to reevaluate strangeness signature of quark--gluon plasma is not able to explain the majority of available experimental results.Comment: 14 pages including 6 figures, submitted to Journal of Physics G Presented at: Strange Quark Matter, September 2001, Frankfur

Strangeness Report

The paper provides a short report on strangeness production in ultrarelativistic nucleus-nucleus collision, with the main stress on strange particle abundances.Comment: Proceedings of Quark Matter 200

Rapidity distributions around mid-rapidity of strange particles in Pb-Pb collisions at 158 AA GeV/c

The production at central rapidity of K0s, Lambda, Xi and Omega particles in Pb-Pb collisions at 158 A GeV/c has been measured by the NA57 experiment over a centrality range corresponding to the most central 53% of the inelastic Pb-Pb cross section. In this paper we present the rapidity distribution of each particle in the central rapidity unit as a function of the event centrality. The distributions are analyzed based on hydrodynamical models of the collisions.Comment: 15 pages, 10 figure

Study of the transverse mass spectra of strange particles in Pb-Pb collisions at 158 A GeV/c

The NA57 experiment has collected high statistics, high purity samples of \PKzS and \PgL, $\Xi$ and $\Omega$ hyperons produced in Pb-Pb collisions at 158 $A$ GeV/$c$. In this paper we present a study of the transverse mass spectra of these particles for a sample of events corresponding to the most central 53% of the inelastic Pb-Pb cross-section. We analyse the transverse mass distributions in the framework of the blast-wave model for the full sample and, for the first time at the SPS, as a function of the event centrality.Comment: 22 pages, 14 figures, submitted to J. Phys. G: Nucl. Phy

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

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

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

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 studied as a function of centrality within the range covered by NA57 (about 55% most central part of the inelastic cross section). The central rapidity multiplicity varies roughly linearly with the number of wounded nucleons (participants) and increases approximately logarithmically with the centre of mass energy