Microscopic Reaction Dynamics at SPS and RHIC.pdfVIP

1 Microscopic Reaction Dynamics at SPS and RHIC 1 0 Steffen A. Bassa 0 2 r aDepartment of Physics, Duke University, Durham, NC 27708-0305 p RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, NY11973 A 1 1 1. Transport Theory at RHIC 1 v Transport Theory offers the unique capability of connecting experimentally observable 0 4 quantities in a relativistic heavy ion collision with its time evolution and reaction dynam- 0 ics, thus giving crucial insights into the possible formation of a transient deconfined phase 4 0 of hot and dense matter, the Quark-Gluon-Plasma (for reviews on QGP signatures, see 1 e.g. [1,2]). 0 / Figure 1 provides an overview of different transport theoretical ansatzes currently on h the market for the description of a relativistic heavy ion collision at RHIC energies. The t l- timeline shows a best case scenario for what to expect: the formation of a QGP with c u subsequent hadronization and freeze-out. Bands with solid lines denote the safe range of n applicability for the respective transport approach, whereas dashed/dotted bands refer : v to areas in which the approach is still applied but where the assumptions on which the i X approach is based upon may be questionable or not valid anymore. r The initial state and early pre-equilibrium phase are best described in Classical Yang- a Mills theory (CYM) [3] or Lattice Gauge Transport (LGT) [4] calculations - only these classes of models treat the coherence of the initial state correctly, but do not provide any meaningful dynamics for the later reaction stages. The Parton Cascade Model (PCM) [5] and related pQCD approaches [6] treat