Seminar in Hadronic Physics

Soft Photons from transport and hydrodynamics

Bjørn Bäuchle

Universität Frankfurt

Direct photon spectra from A+A-collisions are calculated from the hadronic microscopic transport model UrQMD as well as the macroscopic UrQMD+hydro hybrid model, where the hot and dense phase of the evolution has been replaced by an (3+1)-dimensional ideal fluid dynamic description. We investigate flow patterns as well as the emission time distribution and baryon densities at emission for center-of-mass-energies from E_Lab=35 AGeV to √(s_NN)=2.76 TeV. The difference between purely hadronic emission (in both pure UrQMD and Hybrid model) and hadronic+partonic emission (in Hybrid model only) is investigated.