Münster 2017 – wissenschaftliches Programm
HK 40.5: Vortrag
Donnerstag, 30. März 2017, 15:00–15:15, F 3
Thermal dilepton emission as a fireball probe — •Florian Seck1, Tetyana Galatyuk1,2, Ralf Rapp3, and Joachim Stroth4,2 — 1TU Darmstadt — 2GSI, Darmstadt — 3Texas A&M Univ., College Station, USA — 4Goethe-Universiät Frankfurt
Collisions of heavy ions at (ultra-)relativistic energies offer the opportunity to explore strongly interacting matter across the QCD phase diagram. Electromagnetic probes are an excellent tool for these investigations as they are emitted during the whole evolution of the collision and decouple from the interaction zone once they are produced. They carry information about the properties of matter created inside the hot and dense fireball to the detector which is irretrievable from the spectra of final-state hadrons due to rescattering. In particular, the yield of thermal low-mass dileptons is sensitive to the fireball lifetime, while the slope in the intermediate-mass region of the dilepton invariant-mass spectrum can serve as a true thermometer of the medium.
Realistic thermal dilepton emission rates and a coarse-graining method for the fireball’s space-time evolution are utilized to properly describe the contribution of in-medium signals to the dilepton invariant-mass spectrum. The obtained results will be compared to the excitation function of the lifetime and temperatures of the fireball established at higher energies. The results can serve as a baseline for future explorations by the HADES and CBM experiments at FAIR as well as the RHIC beam energy scan phase II.
This work has been supported by: VH-NG-823, Helmholtz Alliance HA216/EMMI and GSI.