Comparison of heavy ion transport simulations: Ag + Ag collisions at E lab = 1.58A GeV

We compare the microscopic transport models UrQMD, PHSD, PHQMD, and SMASH to make predictions for the upcoming Ag + Ag data at E-lab = 1.58A GeV (root S-NN = 2.55 GeV) by the HADES collaboration. We study multiplicities, spectra and effective source temperatures of protons, pi(+/-,0), K-+/- , the eta, Lambda +Sigma(0) and the Xi(-) within these models. Despite variations in the detailed implementation of the dynamics in the different models, the employed transport approaches all show consistent multiplicities of the bulk of investigated hadrons. The main differences are in the Xi(-) production, which is treated differently between UrQMD/SMASH on one side employing high mass resonance states with explicit decays to Resonance -> Xi + K + K in contrast to PHSD/PHQMD which account only non-resonant Xi production channels. A comparison of the spectra, summarized by effective source temperatures, shows that all models provide similar source temperatures around T-source = 80-95 MeV, and show substantial radial flow on the order of < v(T)> = 0.18c - 0.24c even for such a small system.