Münster 2017 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 59: Heavy Ion Collisions and QCD Phases XII

HK 59.2: Gruppenbericht

Freitag, 31. März 2017, 14:30–15:00, F 3

Chiral symmetry restoration as seen by the K⁺/π⁺ ratio in heavy-ion collisions from PHSD transport approach — •Alessia Palmese¹, Wolfgang Cassing¹, Eduard Seifert¹, Thorsten Steinert¹, Pierre Moreau², and Elena Bratkovskaya^2,3 — ¹Institute for Theoretical Physics, University of Giessen, Giessen, Germany — ²Institute for Theoretical Physics, Johann Wolfgang Goethe University, Frankfurt am Main, Germany — ³GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt, Germany

The Parton-Hadron-String-Dynamics (PHSD) is a microscopic off-shell transport approach, which successfully describes Heavy-Ion Collisions (HIC) in a wide range of energies from SIS to LHC energies. The PHSD includes the deconfinement phase transition as well as essential aspects of Chiral Symmetry Restoration (CSR) in the dense and hot hadronic medium, which are incorporated in the Schwinger mechanism for the hadronic particle production. We find that the CSR effects can be identified in many observables like particle ratios and rapidity spectra and provide the first microscopic explanation for the ’horn’-structure in the excitation function of the K⁺/π⁺ ratio. We study also the system size and centrality dependence of the strangeness production in HICs, in particular the appearance/disappearance of the ’horn’-structure of the K⁺/π⁺ and (Λ+Σ⁰)/π ratios in A+A and p+A collisions. The impact of CSR on the directed flow of charged hadrons is discussed in context of the data from the beam-energy-scan program at RHIC.