DFG-Project 436 Rus 113/558/0-3 (2000 - 2008):

Non-Equilibrium Strongly Interacting Dense Matter
in Nucleus-Nucleus Collisions

Collaboration:

present members
Yuri B. Ivanov Kurchatov Institute/ Moscow   Bengt L. Friman GSI
Dmitry Voskresensky MIPE/ Moscow     Jörn Knoll GSI
Viatcheslav D. Toneev JINR Dubna   Jochen Wambach GSI/ TU-Darmstadt
Vladimir Skokov JINR Dubna
 
former members
Edward G. Nikonov JINR Dubna   Hendrik van Hees GSI; now Texas A&M
Wolfgang Nörenberg

Publications

Goals and Projects:

One of the main experimental projects planed at the future Facility for Anti-proton and Ion Research (FAIR) at GSI (Darmstadt) addresses the investigation of compressed baryonic matter (CBM) by means of nucleus-nucleus collisions in a beam-energy range of Elab ~ 10 - 40 AGeV. In this energy range, which covers the gap between existing accelerators, the SIS at GSI and the AGS at BNL (Brookhaven) at the low energy side and SPS at CERN (Geneva), the highest baryon densities are expected to be achieved while temperatures remain still moderate. The corresponding area of the phase diagram of the strongly interacting matter close to the phase boundary between the confined phase and the chirally restored deconfined phase is by far less explored, both experimentally and theoretically, than the adjoint regions covered by the existing accelerators. Furthermore astrophysical data provide constraints for the domain of cold and dense matter, while lattice QCD calculations give theoretical inside into the phase structure and thermodynamic properties of the strongly interacting QCD-matter at low net baryon densities.

The main questions the CBM-experiment at the new facility SIS200 is aiming to address to are: (i) do the deconfinement and/or chiral phase transitions occur in this incident-energy range, (ii) if so, what are the orders of the phase transitions, does a critical point exist, and (iii) what are the corresponding observable signals.

Our project addresses these questions from the theory side. We are investigating three closely inter-related aspects which can be briefly denoted as:

  1. Nuclear equation of state (EoS);
  2. Nuclear collision dynamics;
  3. Off-shell transport
The main accomplishment achieved by the collaboration is the programming of a relativistic three-fluid hydrodynamic code as the main work-horse for the description and theoretical investigation of nuclear collisions at high energies. The code has been completed and published on the World-Wide-Web. Exploratory calculations have been performed with a simple equation of state (EoS) in order to test the method. The code is now ready for further physical applications and investigations exploring a variety of physical scenarios with different EoS and different transport properties for the interaction among the three fluids. Alongside progress has been achieved in the construction of phenomenological EoS which include the phase-transition from the hadronic phase to the quark-gluon-plasma (QGP) phase respecting the constraints resulting from Lattice-QCD calculations and also from the low energy systematics of nuclear data and nuclear matter calculations.