Recent results from the NA49 experiment

Recent results of the NA49 collaboration are presented. Transverse mass spectra as well as total multiplicities of identified particles are discussed. The study of their evolution from AGS over SPS to the highest RHIC energy reveals a couple of interesting features. These include a sudden change in the energy dependence of the mt-spectra and of the yields of strange hadrons around 30A GeV. Additionally, new results on particle production at high-pt for Pb+Pb collsions at 158A GeV, as well as on the v2 of L, are discussed

Open Questions in the Understanding of Strangeness Production in HIC -- Experiment Perspective

Open questions concerning strangeness production in heavy-ion collisions are discussed with a focus on the experimental aspects. The open points are presented in the context of recent measurements.Comment: Proceedings for the Strange Quark Matter 2017 conference in Utrecht, Netherland

Review of structures in the energy dependence of hadronic observables

The energy dependence of various hadronic observables is reviewed. The study of their evolution from AGS over SPS to the highest RHIC energy reveals interesting features, which might locate a possible onset of deconfinement. These observables include transverse spectra of different particle types and their total multiplicities, as well as elliptic flow. In this context especially the observation of a maximum of the strangeness to pion ratio is of particular interest, since on one hand it has been predicted as a signal for the onset of deconfinement but on the other hand also statistical model calculations exhibit qualitatively similar structures. The sharpness of these features is however not reproduced by hadronic scenarios. The significance of these structures will be discussed in this contribution. Other observables, such as radius parameters from Bose-Einstein correlations, on the other hand do not exhibit any structure in their energy dependence

Strangeness Production at the SPS

Systematic studies on the production of strange hyperons and the phi meson as a function of beam energy and system size performed by the NA49 collaboration are discussed. Hadronic transport models fail to describe the production of multi strange particles (Xi, Omega), while statistical models are generally in good agreement to the measured particle yields at all energies. The system size dependence is well reproduced by the core-corona approach. New data on K*(892) production are presented. The yields of these short-lived resonances are significantly below the statistical model expectation. This is in line with the interpretation that the measurable yields are reduced due to rescattering of their decay products inside the fireball.Comment: Proceedings to the ISMD09 Conference. 5 pages, 6 figure