Dr. Volker Friese, GSI, Darmstadt, Niemcy

Strangeness and the phi-meson in heavy-ion collision

The production of particles containing strange quarks is considered a key observable for the understanding of the reaction mechanisms in relativistic heavy-ion collisons. Recent results from the CERN-SPS, observing an anomaly in the relative strangeness production at around 30 AGeV, have been interpreted as a signature for the onset of a transition towards a deconfined state of matter, the quark-gluon plasma. The phi meson has a particular role due to being strangeness-neutral, yet containing a s-sbar quark pair. Thus, hadronic and partonic scenarios for strangeness creation will have quite different impacts on the production of phi mesons. In this lecture, we will present and discuss recent experimental results on strangeness production in heavy-ion collisions, with emphasis on data on phi mesons obtained by the NA49 collaboration. An outlook on the experimental propects from future experiments will be given.