Figure 1

$\pt$-differential yields of ${\rm K}^{0}_{S}$, $\Lambda+\overline{\Lambda}$, $\Xi^{-}+\overline{\Xi}^{+}$ and $\Omega^{-}+\overline{\Omega}^{+}$ measured in $\left|y\right| < 0.5$. The results are shown for a selection of event classes, indicated by roman numbers in brackets, with decreasing multiplicity. The error bars show the statistical uncertainty, whereas the empty boxes show the total systematic uncertainty. The data are scaled by different factors to improve the visibility. The dashed curves represent Tsallis-Lévy fits to each individual distribution to extract integrated yields. The indicated uncertainties all represent standard deviations.