Transverse Pressure and Strangeness Dynamics in Relativistic Heavy Ion Reactions

Transverse hadron spectra from proton-proton, proton-nucleus and nucleus-nucleus collisions from 2 AGeV to 21.3 ATeV are investigated within two independent transport approaches (HSD and UrQMD). For central Au+Au (Pb+Pb) collisions at energies above Elab ∼ 5 AGeV, the measured K transverse mass spectra have a larger inverse slope parameter than expected from the default calculations. The additional pressure as suggested by lattice QCD calculations at finite quark chemical potential μq and temperature T might be generated by strong interactions in the early pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions. This is supported by a non-monotonic energy dependence of v2/〈pT 〉 in the present transport model. Transverse Pressure and Strangeness Dynamics in Relativistic Heavy Ion Reactions 2