3-D Jet Tomography: A Probe of the Hydrodynamic Initial State in Heavy Ion Collisions Original Research Article

Recent studies have shown that the hypothesis of “perfect” QCD fluid being produced at RHIC is heavily influenced by the assumptions used concerning the initial state input to ideal hydrodynamics. In an effort to differentiate between the different models for the initial state at RHIC (Participant and Color Glass Condensate (CGC)), we propose 3-D Jet Tomography in the (p⊥,ϕ,η) plane as a test to experimentally differentiate the models. We decompose RAA(ϕ;p⊥,η) into fourier modes in ϕ and show that the observable v1(p⊥,η) may differentiate between Participant and CGC type initial state models.