Physical Review Letters 92,18 (2004) 182301;
The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (&UXi;) over bar (+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.
strangeness production;; particle ratios;; equilibration;; sps
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