1 IntroductionStrange particles, produced in high-energy heavy-ion collisions, are amongstthe most powerful tools for the study of reaction dynamics. What makes thisfield of research particularly challenging is the prediction that the yield ofstrange, and especially multiply-strange, (anti-) particles should be stronglyenhanced in the presence of a quark-gluon plasma (QGP) as compared to apurely hadronic scenario at the same temperature

Lambda, Xi and Omega yields measured by the WA97 experiment at central rapidity in p-Pb interactions at 158 GeV/c are compared to those predicted by VENUS 4.12. The VENUS model, although in reasonable agreement with the Lambda and the negative particle data, fails to reproduce the data on multistrange baryons and anti-baryons.

Lambda, Xi and Omega yields and transverse mass spectra measured at central rapidity in Pb-Pb and p-Pb collisions at 158 A GeV/c are presented. The yields in Pb-Pb interactions are given as a function of the collision centrality and compared with those obtained from p-Pb collisions. The dependence of hyperon yields on the centrality of the impact and on the strangeness content of the hyperon are discussed.

The first results on V-0-V-0 pairs, namely invariant masses and HBT correlations, obtained by the WA97 experiment in Pb-Pb collisions are presented. There is no evidence for any resonance signal.

Λ, Ξ and Ω yields and transverse mass spectra have been measured in Pb-Pb and p-Pb collisions at 158 A GeV/c. The yields in Pb-Pb interactions are presented as a function of the collision centrality and compared with those obtained from p-Pb collisions. Strangeness enhancement is observed which increases with centrality and with the strangeness content of the hyperon.

A, Ξ and Ω yields and transverse mass spectra have been measured in Pb-Pb and p-Pb collisions at 158A GeV/c. The yields in Pb-Pb interactions are presented as a function of the collision centrality and compared with those obtained from p-Pb collisions. Strangeness enhancement is observed which increases with centrality and with the strangeness content of the hyperon.

Enhanced production of strange baryons and anti-baryons at central rapidity in S-W and S-z.sbnd;S with respect to p-A reactions has been reported by the CERN experiments WA85 and WA94. The WA97 experiment is extending such a study to PbPb collisions making use of the newly developed silicon pixel detectors.

New data from the CERN WA97 experiment on Xi and Omega production in p-Pb and Ph-Ph collisions at 158 GeV/c per nucleon are presented. They confirm the recent indication(1) that the Omega/Xi ratio is significantly higher in Ph-Ph compared to p-Ph reactions.

The WA94 collaboration uses the production of strange and anti-strange particles to investigate the properties of hot hadronic matter created in heavy-ion interactions. Λ,\(\bar \Lambda \), Ξ− and\(\bar \Xi ^ + \) particle yields and transverse mass spectra are presented for pS interactions and are compared with those for SS interactions and for the pW and SW interactions of WA85.

Preliminary results from WA97 measurements on Λ, Ξ and Ω production in lead-lead and proton-lead collisions are presented, along with a comparison of WA97 proton-lead data with previous WA85 proton-tungsten results. The ratio ΩgX seems to be enhanced in lead initiated reactions compared to proton initiated reactions.

Preliminary results from WA97 measurements on Λ, Ξ and Ω production in lead-lead and proton-lead collisions are presented, along with a comparison of WA97 proton-lead data with previous WA85 proton-tungsten results. The ratio Ω/Ξ seems to be enhanced in lead initiated reactions compared to proton initiated reactions.