"Hard" results 4: Elliptic flow [nucl-ex/0204005]

• Initial anisotropy in coord. space (overlap in non-central collisions) translates into final azimuthal asymmetry in momemtum space in the transv. plane

• Exp. correlation functions: pT and centrality dependence of v2 (A2):

• Strong (integrated & differential) elliptic flow signal Þ strong (collective) pressure gradients Þ large initial state (t<1.0 fm/c) parton rescattering (early thermalization).

  • Important elliptic flow signal: strong early time rescattering (equilibration)
  • Comparison to relativistic hydrodynamical models (EoS) possible.