Strangeness production in heavy-ion collision at energies below the free NN production threshold is an excellent tool to study medium properties of dense baryonic systems. For the first time, a nearly complete set of strange particles has been reconstructed in the 40% most central Au+Au collisions at $1.23 A$ GeV. The data sample includes multi-differential representations of charged and neutral Kaons, Lambdas and Phi-mesons. The multiplicities, together with those for non-strange hadrons, have been analyzed in the context of statistical hadronization models. Overall, a good fit is obtained if an additional parameter ($R_c$) is used to account for canonical strangeness suppression. We find that about 30 % of observed $K^-$ are produced through Phi-decay. If we correct the observed $K^-$ transverse momentum spectra for feed down from $\phi$ decay, all extracted slope parameters also support the assumption of a homogenous emission source for all particle types.
|Preferred Track||Baryon-Rich QCD Matter and Astrophysics|